* fix: delete chart or dashboards with assoc reports
* database constraint to reports and tests
* add tests for dashboards and database
* fix exceptions default text
* [mypy] Enforcing typing for superset.dashboards
* Make return types equal on all commands
* Make return types equal on all commands
* [dashboard] address comments same return type on commands
* lint
* lint
* [dashboard] Refactor API using SIP-35
* [dashboard] Fix, import
* [dashboard] more tests
* [dashboards] a misc of improvements
* [charts] Fix, DAO and tests
* [dashboards] small exceptions refactor
* [dashboards] lint
* [dashboards] Improves comments on base classes
* [dashboards] lint