Add ability to specify what fields to clone on "Save as Copy" (#6379)

* Start on tree-select component

* Stop propagation on label click as well

* Setup temp debug route

* Add value-combining=all

* Add branch mode

* Add leaf mode

* Add indeterminate state

* Add search

* Keep group state alive during search

* Fetch existing item based on clone fields data

* Add interface for setup

* Tweak field structure of m2a items

* Use collection name in checkbox

* Remove temp test

api/src/database/system-data/fields/collections.yaml

@@ -192,6 +192,6 @@ fields:
   - field: item_duplication_fields
     special:
       - json
-    interface: code
+    interface: system-field-tree
     options:
-      language: JSON
+      collectionField: collection