[BUGFIX] Move EM extension configuration save button to DocHeader

The configuration action brings a Save button.
Save button should be in DocHeader.

Fixes: #46941
Releases: 6.0, 6.1
Change-Id: I05b1c2bf5f6406462ee0a1fcaaa2f5eefbee88f8
Reviewed-on: https://review.typo3.org/19606
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn