[TASK] Cleanup multiple classes of "localPageTree": EXT:impexp

The TYPO3 core has more than one class with the name "localPageTree"
This is not very good, because this classes can`t be loaded via
autoloader due to same names.
The autoloader don`t know which must be loaded.

Solution: Lets clean this mess up!

This patch will handle the localPageTree class in EXT:impexp

Change-Id: I439ddfce66a6d68ddbc774f36e1f285c41cd62e0
Fixes: #38756
Related: #38754
Releases: 6.0
Reviewed-on: http://review.typo3.org/12710
Reviewed-by: Wouter Wolters
Reviewed-by: Susanne Moog
Tested-by: Susanne Moog
Reviewed-by: Stefan Neufeind
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer