Revert "LPS-29988 Rollback as it has not been tested"

This reverts commit 6abf505e3e5b2f78623e9564f29bb182e49f3bc0.
LPS-29988 NPE
LPS-37244 CKEditor shows default icon even if there is an icon for the given file type
LPS-37244 Check if extension is null or empty
LPS-37244 SF
LPS-36001 Integration test

Tests that structures default values document don't get indexed and claim to be NOT indexables.
Changes in JournalTestUtil.java to allow to create articles with different classNameId, needed by the implementation.
LPS-36001 SF
LPS-36001 SF
LPS-34355 Proper initialization of parent class.

Removed references to local variable in favor of parent's getters/setters.
LPS-34355 SF - follow same pattern from Journal and Wiki
LPS-37336 Move export model count logic to a new method (no logic changes)
LPS-37336 Export counters don't consider second level entities
LPS-37336 SF
LPS-34662 Copy and Paste ViewArticleAction (no changes)
LPS-34662 Copy and Paste code (no changes)
LPS-34662 Follow array object pattern to return both the images and the content
LPS-34662 Convert new Action in a PortletAction
LPS-34662 Update new Action to use DDM (content is obtained from the fields in the request) and remove legacy code
LPS-34662 deprecate the old action
LPS-34662 apply changes from @marcellustavares