fixes #18691 - add as_deprecation_tracker to test environment

Causes test failures if any new deprecation warnings are triggered by
changes in Foreman. Plugin code is automatically whitelisted unless it
supplies its own ASDT whitelist configuration, so developers can opt-in....

Fixes #18638 - add sass support to webpack

fixes #18551 - skip table_exists? error when the DB doesn't exist

MySQL and PostgreSQL DB adapters now throw a connection error under
Rails 5 if the the DB doesn't already exist, as the schema cache is no
longer used to answer the method call.

Fixes #7495 - Create/delete autosign entries via API

Fixes #18530 - fix package.json dependencies

fixes #13618 - cache expensive vmware api calls

fixes #18233, #18235 - isolate pagelets state between tests

Moves pagelets state into instances of Pagelets::Manager with clearer
dup semantics, and allows the instance to be backed up and restored
around tests using the PageletsIsolation test case mixin.

Refs #15779 - make background processing unavailable for now (#4217)

The original PR got vetted in the packaging phase and including
foreman-task as dependency of Foreman was refused. We need to rethink
our approach for getting the foreman-tasks functionality available...

fixes #18208 - replace audited-activerecord with audited (#4218)

fixes #17545 - adds UI notification support

- Initial data model for notification support, based on manageiq design.
- addes notification JSON endpoints.