Emit a new hook, when a file is being updated only
The write-hook also is triggered for created files

Fix #8131
Correctly emit create/update hooks when a large file is being created/update
after being uploaded in .part files

Fix #8131
Deduplicate code
Update tests to test for create and update aswell
Remove unneccessary statement from test
Merge pull request #8132 from owncloud/issue/8131

Issue/8131 Fix emitting of filesystem related hooks