Add a search field to the entry type selector

[mmikkel]

It'd be great if the entry type selector could have a search/filter field; similarly to the field layout element selector HUD in FLDs.

Without a way to search/filter entry types in the selector, once there is more than a few entry types it becomes difficult to find what you're looking for in the narrow scrolling pane. It's possible to type in it to jump around, but that doesn't really work for us since we've adopted a "Prefix -" naming pattern as a way to group similar entry types together.

[thupsi]

Great point! (And I think easy to implement)

[brandonkelly]

Good idea. Added for 5.7 🎉 (#16710)