fixes #19479, #10587, #19500 - two pane notifications are visible

- notification is now inside the content div, allowing two-pane server
responses to include it.
- refactored all notifications to use notification helpers (notice,
warning and error) instead of direct flash manipulation...

fixes #19483 - use #admin? method to check inherited admin flags

Fixes #18995, #18996 - visible_environments works w/o taxonomies

fixes #19476 - list features in smart proxy refresh API response

fixes #14178 - Introduce patternfly toast notifications

fixes #14178 - introduce patternfly toast notifications

- replaces old jnoitfy with react implementation.
- Adds a notification store to handle events from
rails flash + legacy javascript Notice function and expose
an Action API to add notifications.

fixes #19464 - rewrite Dashboard::Manager to support autoloading

Replaces class-level widget storage with a static list of built-in
widgets, then appends the registered plugin widgets to get the full
default list of widgets. As a result, the class can safely be reloaded...

fixes #19463 - disable auditing of factory_girl fixtures

Audit entries are mostly superfluous in the test environment, but can
be enabled by adding the :with_auditing trait. Disabling audits
improves the test:models runtime from 160 to 128 seconds for me.

Fixes #19400 - defer loading of tables list cache

The BookmarkControllerValidator can get loaded sooner than the tables
are loaded (especially in tests).

Fixes #19417 - Safely check params for nested keys