[FEATURE][FIX] sap.ui.layout.Form: Adapt F6 Handling, Smaller bugfixes
in Core F6 Handling

Change-Id: I295b7d5c321918fcbd9d40e81ed3da806cc8f139
Merge "[FEATURE][FIX] sap.ui.layout.Form: Adapt F6 Handling, Smaller bugfixes in Core F6 Handling"