Fixes https://github.com/forem/forem/issues/9683.
Also refactors the initializeBroadcast function to handle all
broadcast-related logic, and removes broadcast checks from the articleForm component.
* Do not render active announcements in mod tools
* Add a TODO around refactoring broadcast initialization
* Refactor initializeBroadcast to short-circuit on window.frameElement
* Provide default crayon styles when creating banners
* Import crayons styles into /internal pages.
* Allow admins to use crayons banner styles when creating broadcasts.
* Preview banner styles with crayons.
* Add a "x" close button to announcements, fix styling to accommodate it
* Use constant and helper for broadcast banner styles
* Add VALID_BANNER_STYLES frozen constant to Broadcast class.
* Add banner_style helper for determining banner style class.
* Clean up preview CSS, import broadcast styles into preview
* Add close button click handler, clean up initializeBroadcast
* Add close functionality to announcement banner
Also hide announcement if the user has explicitly seen and "X"-ed out of it.
* Add system specs around rendering + dismissing broadcasts
* Add some (truly beautiful) JS documentation
* Add visible class to broadcast when previewed from internal
* Provide default crayon styles when creating banners
* Import crayons styles into /internal pages.
* Allow admins to use crayons banner styles when creating broadcasts.
* Preview banner styles with crayons.
* Use constant and helper for broadcast banner styles
* Add VALID_BANNER_STYLES frozen constant to Broadcast class.
* Add banner_style helper for determining banner style class.
* Serialize broadcast_data within AsyncInfoController::base_data
Adds a `broadcast:` key to our `base_data`, regardless of whether a user is logged in or not.
If a broadcast is not present, passes along a `nil` value.
* Initialize active broadcast (if present) when rendering main page
* Allow admins to preview a broadcast's processed_html when editing
* Add some fixed position styling to active broadcast
* Add system specs around broadcasts on homepage
* Use sanitize in place of html_safe when previewing broadcast
* Do not initialize broadcast if no broadcastData available
* Render default value on broadcast in options_for_select
* JS cleanup
* Unset fixed positioning for static navbar config
Also add some default styling for an active broadcast
