[Improvement]: Default value input fields for Multiselect (#252)

* add default value and default value generator input fields

* Add default value grid for multiple default values

* Resolve conflicts

* Update public/js/pimcore/object/classes/data/multiselect.js

Remove console log

Co-authored-by: Jacob Dreesen <[email protected]>

* Use let and const

* Update namespace and fix class.js error

* hide plain default value field

* fix editor and column (not prepended by comma), add changelog

* default values limit tied to the max selectable value

* remove console log

* disable the grid for the dynamic options, fix var with let/const

* revert change

* fix normal select

* fix maxitems 0

---------

Co-authored-by: Jacob Dreesen <[email protected]>
Co-authored-by: mattamon <[email protected]>
Co-authored-by: Ji Jia Jia <[email protected]>

Author: 4 people

CHANGELOG.md

@@ -1,3 +1,6 @@
+#### v2.1.0
+- Added the possibility to set default values for multi select fields in class definitions.
+
 #### v1.6.0
 - Show tree search even if all child elements fit on one page (according to `tree_paging_limit`) - if there are at least 30 children in total
 - Prevent accidental deletion of folder if items get selected in grid and then the "Delete folder" button gets clicked. Instead: If grid items are selected, delete button asks if the selected items should be deleted. If no grid items are selected, the folder gets deleted (after confirmation).