This PR addresses several items listed in our rubocop_todo by implementing the necessary corrections and enhancements. As a result, we are now able to remove the rubocop_todo file entirely, streamlining our codebase and ensuring adherence to our coding standards.
fixes: https://linear.app/chatwoot/issue/CW-1806/chore-rubocop-audit
* Add annotate gem to the project
* Annotate models, fixtures, factories and model_specs
* Keep annotations only in Models
* Remove unwanted changes in model specs
* Exclude auto_annotate_models from rubocop
