[BUGFIX] Remove save and new button for sys_file

The save and new button does not make any sense for file
meta data, so we should not display it.

Resolves: #45044
Releases: 6.0, 6.1

Change-Id: Ic25edee5b208103f74c7d566acb93099bdd3c19f
Reviewed-on: https://review.typo3.org/17898
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel
[TASK] DataHandler::getAutoVersionId() should be public

The method getAutoVersionId() in DataHandler/t3lib_TCEmain
should be public. The method is a helper to access the accordant
member variable that get's filled during workspace actions and
thus is useful in hooks as well.

Change-Id: Ie1f55d92b8e72e6ab68a563f0c1c52762239e102
Resolves: #45050
Releases: 6.1, 6.0, 4.7, 4.6, 4.5
Reviewed-on: https://review.typo3.org/17903
Reviewed-by: Oliver Hader
Tested-by: Oliver Hader