TMDM-7966: "No change reported while adding a mandatory complex type to an entity "

Fix missing message when a reusable type is added.
Amend existing unit test following additional provided information by QA.
(https://jira.talendforge.org/browse/TMDM-7966)
TMDM-7962 : Multiple elements aren't displayed while using CustomLayout
TMDM-7977 Journal statistics do not update and refresh shows error.
-Fixed NPE issue

https://jira.talendforge.org/browse/TMDM-7977
Merge branch 'maintenance/5.6'