New dav doesn't return resources if auto accepting enabled

[ScharfViktor]

case with disabled autoaccepting

• start ocis with FRONTEND_AUTO_ACCEPT_SHARES: "false"
• marie shares folder disabled to admin
• admin accepts folder disabled and can get folder using curl -XPROPFIND "https://host.docker.internal:9200/remote.php/dav/files/admin/Shares/disabled" -uadmin:admin -H "Content-Type: application/json" -vk

Actual: request returns folder

case with enabled autoaccepting

• start ocis with FRONTEND_AUTO_ACCEPT_SHARES: "true"
• marie shares folder enabled to admin
• admintries to get folder enabled curl -XPROPFIND "https://host.docker.internal:9200/remote.php/dav/files/admin/Shares/enabled" -uadmin:admin -H "Content-Type: application/json" -vk

Actual: not found: <d:error xmlns:d="DAV" xmlns:s="http://sabredav.org/ns"><s:exception>Sabre\DAV\Exception\NotFound</s:exception><s:message>Resource not found</s:message>

but space dav works fine: curl -XPROPFIND "https://host.docker.internal:9200/remote.php/dav/spaces/a0ca6a90-a365-4782-871e-d44447bbc668%210be2e235-4298-416a-aad0-4bdf2aaff6e6:f7fbf8c8-139b-4376-b307-cf0a8c2d0d9c:5d657ace-1e41-49ed-b044-e54c07067166/" -uadmin:admin -H "Content-Type: application/json" -vk

[kobergj]

Underlying issue is the same as in #7441 - no mountpoint is set.