* refactor: remove dead code
* refactor: remove ignore YieldsMessageAttribute
- the correct one to use is YieldsOutputAttribute
- fixes a comment that mistakenly refers to `.YieldsMessage()` which does not exist.
* fix: ChatForwardingExecutor does not use correct role for string messages
- make ChatForwardingExecutor use its configured role for string messages rather than always use ChatRole.User
- add ChatForwardingExecutor tests
* fixup: remove unused attribute
* test: Add tests for failure when .AsAgent used on a non-ChatProtocol workflow
* test: Add FunctionExecutor tests
- also fixes Send and YieldOutput type registration for synchronous output-returning delegates
* test: Suppress CodeCoverage for obsolete names
* fix: Re-add Obsolete attributes
- avoid hard-breaking change
- properly notify users that these attributes get ignored
Jacob Alber