Allow search by Name in the Actions dialog.

# Description of the new feature/enhancement
The actions list in the action settings dialog is large, and it's difficult to search for a specific item, so It would be useful to have some search feature, such as an input dialog which allows filter them by name.

# Proposed technical implementation details (optional)
Add an input dialog at the top of the dialog which filters the actions list as the user typing.

Start by locating the Actions settings dialog and the code that builds its actions list. Add a name filter that updates as the user types, and consider the work complete when users can quickly find actions by name in the dialog.

Written by the indexing model from the issue text.