Fixes #19418 - Correctly route cancel button on host form

Fixes #19646 - improve inline help

Fixes #19700 - update rubocop rules

The following changes have been made:

- Performance/RedundantMerge:
changes lines such as:
```not_found_message.merge! :message => options```
to:
```not_found_message[:message] = options```

- converts str.match() to str =~ ()...

fixes #19340 - replace all new_host calls with new_vm

Fixes #16159 - Rename mail alerts to not be Puppet specific

Right now, under 'my account', users get emails with alerts about the
status of their hosts regarding configuration management (e.g: if there
was an error, get an alert, or get a weekly summary of all hosts...

Fixes #19296 - Combination remove link shows correct tooltip

Fixes #19384 - Add tooltip to the Remove Matcher button

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 #19476 - list features in smart proxy refresh API response

templates - sync from community-templates