Merge branch 'master' into feat/fetch_roles_for_dashboard

* master: (30 commits)
  refactor(native-filters): decouple params from filter config modal (first phase) (apache#13021)
  fix(native-filters): set currentValue null when empty (apache#13000)
  Custom superset_config.py + secret envs (apache#13096)
  Update http error code from 400 to 403 (apache#13061)
  feat(native-filters): add storybook entry for select filter (apache#13005)
  feat(native-filters): Time native filter (apache#12992)
  Force pod restart on config changes (apache#13056)
  feat(cross-filters): add cross filters (apache#12662)
  fix(explore): Enable selecting an option not included in suggestions (apache#13029)
  Improves RTL configuration (apache#13079)
  Added a note about the ! prefix for breaking changes to CONTRIBUTING.md (apache#13083)
  chore: lock down npm to v6 (apache#13069)
  fix: API tests, make them possible to run independently again (apache#13076)
  fix: add config to disable dataset ownership on the old api (apache#13051)
  add required * indicator to message content/notif method (apache#12931)
  fix: Retroactively add granularity param to charts (apache#12960)
  fix(ci): multiline regex in change detection (apache#13075)
  feat(style): hide dashboard header by url parameter (apache#12918)
  fix(explore): pie chart label bugs (apache#13052)
  fix: Disabled state button transition time (apache#13008)
  ...