TMDM-7517: implementation for portlets remove/restore/diable i18n

TMDM-7517: code refactoring and clean-ups

TMDM-7517: code refactoring - using non static methods

TMDM-7517: labels translations

TMDM-7517: final translation and UI adjustment

TMDM-7517: corrects wrong translations
TMDM-7517: add updates missed during rebase
TMDM-7573: "The 'concatenate' survive rule in t-swoosh should receive a separator as parameter"

Adds support for an optional parameter in concatenate action (when performing incremental updates).
(https://jira.talendforge.org/browse/TMDM-7573)
Merge branch 'maintenance/5.6'