First version of search-based ID browsing. Now only in use for the
top bar screen/scene browse. The python buttons will follow.
Also made search button colors match the theme colors from menu back.
Todos for browse-search:
- "Add new" will disappear, and become a separate icon button in the
row of widgets (like X, delete).
- Drawing the preview icons in menu
- Make search menu dynamic, with configurable number of items? And/or
multi-collumn... for now it's static
- Search menu should popup with last active ID visible and selected