Support for custom EventBridge event buses

Is there any plan to support more EventBridge functionality? In particular, custom event buses. If I create a chalice project and use the app.schedule or app.on_cw_event annotations, Chalice generates EventBridge rules on the default event bus. It would be even better if I could specify a customer event bus instead.

Start by tracing the app.schedule and app.on_cw_event annotations through Chalice's EventBridge rule generation, focusing on where the default event bus is selected. Done means a project can specify a custom event bus and generated rules use it instead of the default; check the existing annotation and deployment tests for expected behavior.

Written by the indexing model from the issue text.