[TASK] Implement CSRF protection for TCEforms file upload

TCEforms file upload must use CSRF protection to work with TYPO3 6.2.

Releases: 3.0
Resolves: #58734
Change-Id: Ib93c93959d4fee297a5c5d00d327ac0a4187ae33
Reviewed-on: https://review.typo3.org/30029
Reviewed-by: Fabien Udriot
Tested-by: Fabien Udriot