* Refactor `get_history_collection` by overloading
* Return error when model doesn't have history collection
* Refactoring
* Remove unnecessary function
* Refactor add_conversation
* Make conversation model id necessary for deleting conversation
* Fix conversation models and conversations
* Remove unnecessary op in the test
* Fix persistence of conversations
* Fix conversaton swap
* Move TTL and conversation history logic to conversation models
* Fix conversation tests
* Fix tests
* Use collections to store conversations
* Use conversation model to select conversation history collections
* Fix multi search add conversation call
* Add support for migrating conversation models
* use same suffix for all default conversation collections
* delete `delete_models_With_conversation_collection`