Implement merge-concrete-entities function and add some tests

[bmerkle]

first implementation of missing merge-concrete-entities function
please have a look if the semantic and implementation is ok.
if yes, we could also add some further test cases.

[gvanrossum]

This ought to be consistent with the TS version at
https://github.com/microsoft/TypeAgent/blob/120e280c7b2acfeb499b5bbc5d78cea23f75b531/ts/packages/knowPro/src/knowledgeMerge.ts#L144C8-L144C38

I'm experimenting with copilot review -- hopefully it can do the check for us.

[Copilot]

Pull request overview

This PR implements the previously unimplemented merge_concrete_entities function, which merges a list of concrete entities by name, combining their types and facets. The implementation includes comprehensive test coverage with 9 test cases covering various merging scenarios.

• Replaces NotImplementedError stub with working implementation using a dictionary-based merging strategy
• Adds helper classes and functions (_MergedEntity, _facets_to_merged, _merged_to_facets) to support the merging logic
• Implements comprehensive test suite covering edge cases including empty lists, single entities, distinct entities, case sensitivity, type deduplication, and facet merging

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.

File	Description
src/typeagent/knowpro/knowledge.py	Implements merge_concrete_entities function with helper classes and functions for merging entities by name, combining types (sorted and deduplicated) and facets (concatenated with "; " separator)
tests/test_knowledge.py	Adds 9 comprehensive test cases covering various merge scenarios including empty inputs, single entities, distinct entities, case sensitivity, type/facet merging, and deduplication

[gvanrossum]

@copilot Please review this function carefully. It should be equivalent in semantics to the TypeScript function mergeConcreteEntities defined here:
https://github.com/microsoft/TypeAgent/blob/120e280c7b2acfeb499b5bbc5d78cea23f75b531/ts/packages/knowPro/src/knowledgeMerge.ts#L144C8-L144C38

[gvanrossum]

@bmerkle Feel free to ignore or implement Copilot's suggestions (or let it implement some itself). I am still waiting for it to compare the Python version to the TypeScript version.

[bmerkle]

@gvanrossum added your review and should be ready now