Better error messaging when schema is updated

[cpacker]

Describe the bug

When the schema is updated (eg on a hot build) memgpt run will fail:

Traceback (most recent call last):
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1967, in _exec_single_context
    self.dialect.do_execute(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 924, in do_execute
    cursor.execute(statement, parameters)
sqlite3.OperationalError: no such column: agents.system

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/bin/memgpt", line 6, in <module>
    sys.exit(app())
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/typer/main.py", line 328, in __call__
    raise e
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/typer/main.py", line 311, in __call__
    return get_command(self)(*args, **kwargs)
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/click/core.py", line 1157, in __call__
    return self.main(*args, **kwargs)
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/typer/core.py", line 783, in main
    return _main(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/typer/core.py", line 225, in _main
    rv = self.invoke(ctx)
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/click/core.py", line 1688, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/click/core.py", line 1434, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/click/core.py", line 783, in invoke
    return __callback(*args, **kwargs)
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/typer/main.py", line 683, in wrapper
    return callback(**use_params)  # type: ignore
  File "/Users/loaner/dev/MemGPT-fresh/memgpt/cli/cli.py", line 519, in run
    agents = ms.list_agents(user_id=user.id)
  File "/Users/loaner/dev/MemGPT-fresh/memgpt/utils.py", line 531, in wrapper
    return func(*args, **kwargs)
  File "/Users/loaner/dev/MemGPT-fresh/memgpt/metadata.py", line 615, in list_agents
    results = session.query(AgentModel).filter(AgentModel.user_id == user_id).all()
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/orm/query.py", line 2673, in all
    return self._iter().all()  # type: ignore
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/orm/query.py", line 2827, in _iter
    result: Union[ScalarResult[_T], Result[_T]] = self.session.execute(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/orm/session.py", line 2351, in execute
    return self._execute_internal(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/orm/session.py", line 2236, in _execute_internal
    result: Result[Any] = compile_state_cls.orm_execute_statement(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/orm/context.py", line 293, in orm_execute_statement
    result = conn.execute(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1418, in execute
    return meth(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/sql/elements.py", line 515, in _execute_on_connection
    return connection._execute_clauseelement(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1640, in _execute_clauseelement
    ret = self._execute_context(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1846, in _execute_context
    return self._exec_single_context(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1986, in _exec_single_context
    self._handle_dbapi_exception(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2353, in _handle_dbapi_exception
    raise sqlalchemy_exception.with_traceback(exc_info[2]) from e
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1967, in _exec_single_context
    self.dialect.do_execute(
  File "/Users/loaner/Library/Caches/pypoetry/virtualenvs/pymemgpt-JSsUGnlY-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 924, in do_execute
    cursor.execute(statement, parameters)
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) no such column: agents.system
[SQL: SELECT agents.id AS agents_id, agents.user_id AS agents_user_id, agents.name AS agents_name, agents.persona AS agents_persona, agents.human AS agents_human, agents.system AS agents_system, agents.preset AS agents_preset, agents.created_at AS agents_created_at, agents.llm_config AS agents_llm_config, agents.embedding_config AS agents_embedding_config, agents.state AS agents_state, agents.tools AS agents_tools 
FROM agents 
WHERE agents.user_id = ?]
[parameters: ('00000000-0000-0000-0000-000000000000',)]

We should catch this particular kind of error message gracefully and show the user a more informative error message, e.g.:

The schema was likely updated in a new build. Please ask #support in the Discord channel for help.