feat: add embedded knowledge flow

[anchenyi]

https://msazure.visualstudio.com/Microsoft%20Teams%20Extensibility/_workitems/edit/31442700

[codecov]

Codecov Report

Attention: Patch coverage is 98.21429% with 1 line in your changes missing coverage. Please review.

Project coverage is 90.31%. Comparing base (e36b843) to head (1aed7d0).
Report is 14 commits behind head on dev.

Files with missing lines	Patch %	Lines
packages/fx-core/src/core/FxCore.ts	90.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##              dev   #13246      +/-   ##
==========================================
+ Coverage   90.28%   90.31%   +0.02%     
==========================================
  Files         603      604       +1     
  Lines       35888    36040     +152     
  Branches     6965     7173     +208     
==========================================
+ Hits        32401    32549     +148     
  Misses       1514     1514              
- Partials     1973     1977       +4     

Files with missing lines	Coverage Δ
packages/cli/src/commands/models/add.ts	100.00% <100.00%> (ø)
packages/cli/src/commands/models/addKnowledge.ts	100.00% <100.00%> (ø)
...t/driver/teamsApp/utils/CopilotGptManifestUtils.ts	94.94% <100.00%> (+0.69%)	⬆️
packages/fx-core/src/question/constants.ts	96.37% <100.00%> (-0.17%)	⬇️
packages/fx-core/src/question/create.ts	90.39% <100.00%> (+0.03%)	⬆️
...x-core/src/question/options/AddKnowledgeOptions.ts	100.00% <ø> (ø)
packages/fx-core/src/question/other.ts	89.06% <100.00%> (+0.66%)	⬆️
packages/fx-core/src/core/FxCore.ts	90.01% <90.00%> (+0.17%)	⬆️

... and 8 files with indirect coverage changes