[WIP] order mimetypes by extension, remove duplicates, use correct ms office mimetypes, update icons

There are several duplicates and wrong entries for ms office formats in the list of mimetypes. This PR fixes them, updates the icons and provides migration code.
:-1:
```
:-1:

19:08:56     [apply] Errors parsing /var/jenkins/workspace/pull-request-analyser-ng-simple@2/label/vm-slave-02/lib/mimetypes.list.php
19:08:56     [apply] PHP Parse error:  syntax error, unexpected ',' in /var/jenkins/workspace/pull-request-analyser-ng-simple@2/label/vm-slave-02/lib/mimetypes.list.php on line 144
```