The basic idea is very simple. Whenever a supported menu is open, one can just
start typing and this opens a search that contains all the (nested) menu entries.
The main downside is that this collides with accelerator keys. Those are the
underlined characters in each menu. For now, we just enable this new searching
behavior in a few selected menus: Node Add Menu, View3D Add Menu and
Modifier Add Menu.
This new functionality can be enabled for a menu by setting
`bl_options = {'SEARCH_ON_KEY_PRESS'}` to true in the menu type.
The status bar shows `Type to search...` when a menu is opened that supports search.
Pull Request: https://projects.blender.org/blender/blender/pulls/110855
7f9d51853c