- Removed harsh theme color border between search and content.
- Prevented intermediate focus on list container to align arrow & tab
behaviour, and to get to content quicker.
- Tweaked styling to add a little extra shadow and be more rounded to
match other UI areas.
- Added slight horizontal inset when in right sidebar to prevent shadow
being cut-off in most cases.
- Added logic to "drop upwards" if dropping down would take the menu
offscreen.
Intended to fix issues raised in #2681.
Changes up the tri-layout tabs, and the main header menu toggle,
to be buttons while adding better text and keyboard controls.
Updated the component format of a few elements along the way.
Added a document to try to define things.
Updated the loading so components are registed dynamically.
Added some standardised ways to reference other elems & define options
