Ignore Some Messages When Transforming

[WaelKarkoub]

Why are these changes needed?

This PR implements some utilities that can be useful when applying TransformMessages to GroupChatManager. This is also part 1 of 2.

The changes in this PR allow specific messages to be included or excluded during the transformation process based on user-defined criteria.

• filter_configs was improved so the user can have finer control when filtering configs. If the user decides to exclude=False (default), then whichever config matches the filter_dict will be returned (the behavior that is currently in main). If exclude=True then the opposite happens; whichever config matches the filter_dict will be excluded from the final result.

• Some transforms like TextMessageCompressor and MessageTokenLimiter can use the filter_dict concept present in autogen to ignore some messages from being transformed.

Example:

• Let us say we want to ignore all system messages from being compressed, we can pass in a filter_dict={"role": ["system"]}, exclude=True.
• How about when we want to compress messages that only come from a specific agent, filter_dict={"name": ["compress_me_agent"]}, exclude=False.

Future Work:

• PrefixName transform: Prepends every message with a text template, e.g. "The agent {agent_name} said this:". It is useful when API providers don't use the name key in the message.
• FilterMessage: Drops all messages based on the filter_dict you pass in. E.g. we want to drop all system messages from the context.

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.