Paths resolved by configuration include symlinks

[jfacorro]

Describe the bug
In a rebar3 project when building diferent profiles, there are a lot of symlinks created.

The path resolution used when loading the configuration for the server does not take into account if the directory resolved contains a symlink. The resolved list of paths is then used by the indexer, which does check for symlink but by that time it's too late.

To Reproduce
Use erlang_ls with erlang_ls in debug mode. Connect to the node and evaluate the following in the shell:

1> els_utils:find_module(lager).
** exception error: no case clause matching [<<"file:///Users/juan.facorro/dev/erlang-ls/erlang_ls/_build/debug/lib/lager/src/lager.erl">>,
                                             <<"file:///Users/juan.facorro/dev/erlang-ls/erlang_ls/_build/default/lib/lager/src/lager.erl">>,
                                             <<"file:///Users/juan.facorro/dev/erlang-ls/erlang_ls/_build/test/lib/lager/src/lager.erl">>]
     in function  els_utils:find_module/1 (/Users/juan.facorro/dev/erlang-ls/erlang_ls/src/els_utils.erl, line 33)

Expected behavior
Each module is indexed only once.

Actual behavior
Same modules indexed multiple times.

Context

• erlang_ls version (tag/sha): e0172e3
• Editor used: Emacs 26.3
• LSP client used: lsp-mode 20191219.1032