Code blocks in tinymce could sometimes end up exploded into the sub
elements of the codemirror display.
This changes the strategy to render codemirror within the shadow dom of
a custom element while preserving the normal pre/code DOM structure.
Still a little instability when moving/adding code blocks within details
blocks but much harder to break things now.
Used upon areas we usually fade-out to provide a focused user
experience. If the user desires more contrasted we prevent this
behaviour using the prefers-contrast media query.
Related to #2634
Generally seems to cause issues when secure images are in use.
Was added during laravel upgrade but laravel does not use this directly
for its web middleware anyway.
- Updated editor, and other area, styles to look okay in dark mode.
- Used tinyMCE theme generator to create dark mode theme.
- Updated tinymce to latest 4x version.
