Allow users to specify the Docker image to use with Testbed

[afourney]

Why are these changes needed?

When scenarios are run on the Testbed, they previously started from a clean "python:3.11" docker image, pulled from Docker Hub. Dependencies were then installed from the requirements file. This whole process would repeat for each task being evaluated.

This was mostly fine when running simple AutoGen scenarios, but has gotten to be somewhat slow as AutoGen dependencies have gotten heavier, or as new benchmarks require additional dependencies.

Importantly, if no image is specified, this code will build an appropriate one for testing. Specifically it will install AutoGen's dependencies -- but not AutoGen itself, as we often want to test a particular branch pulled and installed from Git. It also includes the 10 libraries listed here: https://learnpython.com/blog/most-popular-python-packages/ , namely:

• numpy
• pandas
• matplotlib
• seaborn
• scikit-learn
• requests
• urllib3
• nltk
• pillow
• pytest

NOTE: The list of libraries to install by default deserves careful consideration. On the one hand, we likely want to assume some basic core libraries are available (e.g., requests, urllib3). On the other hand, determining which libraries are important for a task is often part of solving the task itself (equivalent to automatic tool selection). The decision of which libraries to include should therefore be made very carefully and in advance of considering any benchmarks or problem sets. My current thinking on this is to only pre-install libraries that:

-are basic AutoGen requirements (and so would be installed anyways)
-are common enough to find themselves on lists provided by independent/neutral 3rd parties (as above)

If a given benchmark requires other libraries to run (e.g., sympy for MATH), then it is reasonable to create a Docker Image just for that benchmark.

Related issue number

Closes #985 and commend made by @kevin666aa in #792

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (3a768c3) 26.63% compared to head (7962d07) 26.63%.
Report is 2 commits behind head on main.

Additional details and impacted files

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  Hits         1006     1006           
  Misses       2700     2700           
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[victordibia]

PR looks good.
I think having known useful libraries will improve test bed dev experience. Also devs can update the dockerfile as needed.

[yiranwu0]

LGTM!