Adds the GAIA benchark to the Testbed. This PR depends on #792 (#810)

* Re-added completion logging when using older versions of autogen.

* Extended scenario definitions and templating to include folders.

* Prepare collate_human_eval.py for working with group chat scenarios.

* Converted HumanEval to the folder-based approach, and added GroupChat scenarios.

* Fixed the default termination message.

* Fixed another termination condition.

* Updated compatible autogen versions.

* Added initial support for GAIA benchmark.

* Fixed a bug in executing the finalize scripts.

* Generalized the template further to support multiple folder copy operations.

* Refined GAIA support, and broke scenarios down by difficulty.

* Added some experimental scripts for computing metrics over GAIA. This is a first version, and will likely need refinement.

* Added instructions for cloning GAIA

* Updated README to fix some typos.

* Added a script to format GAIA reslts for the leaderboard.

* Update samples/tools/testbed/scenarios/GAIA/Templates/BasicTwoAgents/scenario.py

Co-authored-by: LeoLjl <3110503618@qq.com>

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Co-authored-by: Qingyun Wu <qingyun.wu@psu.edu>
Co-authored-by: LeoLjl <3110503618@qq.com>