Simplify Azure Ai Search Tool

[jay-thakur]

Why are these changes needed?

Simplified the azure ai search tool and fixed bugs in the code

Related issue number

"Closes #6430 "

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://github.com/microsoft/autogen/blob/main/CONTRIBUTING.md 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]

Codecov Report

Attention: Patch coverage is 83.92857% with 45 lines in your changes missing coverage. Please review.

Project coverage is 79.52%. Comparing base (978cbd2) to head (ac614a7).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...ogen-ext/src/autogen_ext/tools/azure/_ai_search.py	81.30%	43 Missing ⚠️
...autogen-ext/src/autogen_ext/tools/azure/_config.py	96.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6511      +/-   ##
==========================================
+ Coverage   79.31%   79.52%   +0.20%     
==========================================
  Files         225      225              
  Lines       16694    16641      -53     
==========================================
- Hits        13241    13233       -8     
+ Misses       3453     3408      -45     

Flag	Coverage Δ
unittests	79.52% <83.92%> (+0.20%)	⬆️

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[ekzhu]

Looks fine to me. Though work with Ben on ensuring the scenario he has can work would be great.