* Add consistent message filtering to all providers.
* Remove old chat history filtering classes
* Fix merge issues
* Fix unit test
* Enforce non-nullable property
* Fix merging bug and make troubleshooting source info easier by adding tostring implementation
* Update message source code to match python.
* Apply suggestion from @Copilot
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* Address PR comment
* Move setting of source information to extension method
* Add underscore for attribution key to indicate internal usage
* Stick to version 102 of the SDK since 103 is causing issues.
* Revert global.json change
* Fix unit test
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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>