Refs #22285 - Prepare UI for strong params enforcement

- Fix current_url_params helper for strong params
Explicitly permit only the permitted parameters, don't try to permit all
parameters (and raise exception for other parameters)
- Don't send editor params to server...

Fixes #21112 - Only initialize host preview once

Instead of adding the event every time the form is loaded, only do it
once when the editor is initialized.

Fixes #20900 - Combine Template editor and template field

Fixes #20240 - fix fullscreen mode in ace editor

fixes #12419 - template preview host has typeahead

fixes #16288 - moves ace editor to webpack.

I've tried to limit changes to minimum, besides fixing lint errors i've:
- moved to brace package (as its compatable with br and webpack).
- added ERB as a syntex highlight.

Fixes #12005 - align host selector for template preview

Fixes #11625: refactor the ace editor to make it reusable.

Make the ace editor reusable and include it on the global parameters
page.

http://projects.theforeman.org/issues/11625