[TASK] RTE: Remove directories pi1, pi2 and pi3

Remove directories pi1, pi2 and pi3 and adapt configuration of spell
checker, frontend RTE and click enlarge features accordingly.

Releases: master
Resolves: #62632
Change-Id: Idc9954d4eb3e03aba5f1b042f1dbc2f0dabc2d88
Reviewed-on: http://review.typo3.org/33727
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Stanislas Rolland <typo3@sjbr.ca>
Tested-by: Stanislas Rolland <typo3@sjbr.ca>