Move the file sharing app to migration

[nickvergessen]

• Move existing update code to repair step
• Fix migrating from OC to NC

[mention-bot]

@nickvergessen, thanks for your PR! By analyzing the history of the files in this pull request, we identified @schiessle, @rullzer and @LukasReschke to be potential reviewers.

[codecov]

Codecov Report

Merging #4812 into master will decrease coverage by 22.84%.
The diff coverage is 0%.

@@              Coverage Diff              @@
##             master    #4812       +/-   ##
=============================================
- Coverage     54.19%   31.35%   -22.85%     
+ Complexity    22149    22135       -14     
=============================================
  Files          1363     1363               
  Lines         84820    84093      -727     
  Branches       1322     1322               
=============================================
- Hits          45966    26364    -19602     
- Misses        38854    57729    +18875

Impacted Files	Coverage Δ	Complexity Δ
.../files_sharing/lib/Migration/SetPasswordColumn.php	0% <0%> (ø)	6 <6> (?)
...s_sharing/lib/Migration/OwncloudGuestShareType.php	0% <0%> (ø)	6 <6> (?)
lib/private/SystemTag/ManagerFactory.php	0% <0%> (-100%)	3% <0%> (ø)
lib/public/Comments/CommentsEvent.php	0% <0%> (-100%)	3% <0%> (ø)
...s/dav/lib/Connector/Sabre/Exception/FileLocked.php	0% <0%> (-100%)	3% <0%> (ø)
apps/user_ldap/lib/Settings/Admin.php	0% <0%> (-100%)	5% <0%> (ø)
lib/private/Share20/Hooks.php	0% <0%> (-100%)	3% <0%> (ø)
lib/private/Repair/NC11/FixMountStorages.php	0% <0%> (-100%)	5% <0%> (ø)
apps/user_ldap/lib/Mapping/UserMapping.php	0% <0%> (-100%)	1% <0%> (ø)
...public/AppFramework/OCS/OCSBadRequestException.php	0% <0%> (-100%)	1% <0%> (ø)
... and 364 more

[rullzer]

Seems to do the job.
👍