feat(trashbin): Add deleted by properties

[Pytal]

• Part of trash bin: show user who deleted that file/folder #14917

Summary

• Store and provide a new trashbin-deleted-by-id and trashbin-deleted-by-display-name DAV properties

• Example PROPFIND request data

<?xml version="1.0"?>
<d:propfind xmlns:d="DAV:" xmlns:oc="http://owncloud.org/ns" xmlns:nc="http://nextcloud.org/ns">
  <d:prop>
    <oc:fileid />
    <d:displayname />
    <d:getlastmodified />
    <d:getcontenttype />
    <oc:size />
    <oc:owner-id />
    <oc:share-types />
    <nc:sharees />
    <nc:share-download-limits />
    <nc:trashbin-filename />
    <nc:trashbin-deletion-time />
    <nc:trashbin-original-location />
    <nc:trashbin-title />
    <nc:trashbin-deleted-by />
  </d:prop>
</d:propfind>

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[Pytal]

Switched the column back to nullable to fix potential migration errors with oracle which converts empty string to null

[come-nc]

Did you test that with groupfolders?

[Pytal]

Did you test that with groupfolders?

Seems it breaks groupfolders as it implements a custom trash backend, documented the change here nextcloud/documentation#11757

App devs will have to update their custom trash backends to support this for 30