Feature: #97664 - Add search functionality to form manager

See forge#97664

Description

It can be difficult for an editor to find the right form definition to edit, if there are many form definitions in the system. To make it easier, a search field is displayed in the form manager. This allows a case-insensitive search by name or persistenceIdentifier.

Impact

It's now possible to search for a form definition inside the form manager backend module.