Memory component base

[EItanya]

Why are these changes needed?

Currently the way to accomplish RAG behavior with agent chat, specifically assistant agents is with the memory interface, however there is no way to configure it via the declarative API.

Related issue number

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.

[EItanya]

Hey @victordibia, I opened this PR in response to your PR with ChromaDB. I think it's important that memory is configurable via the declarative syntax as well.

[victordibia]

Yup, absolutely correct! also builds on #5149

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.93%. Comparing base (be3c60b) to head (5984a91).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5380      +/-   ##
==========================================
+ Coverage   77.87%   77.93%   +0.05%     
==========================================
  Files         158      158              
  Lines        9520     9539      +19     
==========================================
+ Hits         7414     7434      +20     
+ Misses       2106     2105       -1     

Flag	Coverage Δ
unittests	77.93% <100.00%> (+0.05%)	⬆️

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[EItanya]

Ok, I think I fixed up the formatting and tests!