[BUGFIX] Changing capitalization of BE module names

Changes the two-word backend module names to be uppercased (the
first character of both words). This changes the locallang files in setup,
lowlevel and taskcenter system extensions.

Change-Id: I38842f4945dafbf395e35f9a2c1d6a5a917dd403
Resolves: #22256
Reviewed-on: http://review.typo3.org/4384
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer