[BUGFIX] DocumentEditController save with translation broken

With changing the input type=image to input type=submit,
the x/y values are no longer transferred the
EditDocumentController checked for, and content is no
longer saved. Adapt the controller code for the new parameters.

Resolves: #76649
Releases: 8.7, master

Change-Id: I921b92f1086e142592fc84083656c4baecd43aa7
Reviewed-on: https://review.typo3.org/52730


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>