LPS-50645 validate folder name

Make folders with the same parent unique by name.
LPS-50645 add error messages to the view
LPS-50645 make folder name required
LPS-50645 Do not use templatePath variable because it's only accessible from admin portlet so we can safely hardcode it
LPS-50645 Add Language key
LPS-50645 Set required in portlet-model-hints
LPS-50645 autogenerated
LPS-50645 SF
LPS-50645 lang keys
LPS-50645 Rename exceptions
LPS-50645 Regen
LPS-50619