Release 2.3.0 (#4412)

- move user-preferences to edit submenu
- unify user preferences with other forms
- use light fieldset for all user-edit-forms
- support offcanvas elements
- allow to dynamically inject toolbar buttons (via plugins)
- use interface for formatting dates
- improve docker issue template
- bump version and composer packages

src/Constants.php

@@ -17,11 +17,11 @@ class Constants
     /**
      * The current release version
      */
-    public const VERSION = '2.2.1';
+    public const VERSION = '2.3.0';
     /**
      * The current release: major * 10000 + minor * 100 + patch
      */
-    public const VERSION_ID = 20201;
+    public const VERSION_ID = 20300;
     /**
      * The software name
      */