Add test scenarios for meta endpoint PROPFIND with oc:meta-path-for-user

[phil-davis]

For reference see #40010 and cs3org/reva#2741

https://doc.owncloud.com/server/next/developer_manual/webdav_api/meta.html#meta-files-xml documents that the remote.php/dav/meta endpoint should be accessed by doing a PROPFIND that includes a request body:

<?xml version="1.0"?>
<a:propfind xmlns:a="DAV:" xmlns:oc="http://owncloud.org/ns">
    <a:prop>
        <oc:meta-path-for-user/>
    </a:prop>
</a:propfind>

Currently the test scenarios send an empty body, and oC10 replies with the oc:meta-path-for-user data item anyway.

But implementations do not have to do that. An implementation can be coded to only return the oc:meta-path-for-user data if it was explicitly requested.

Keep some of the existing "no body" test cases, so that we still test that. But also add test scenarios that send the documented body, and verify that the correct oc:meta-path-for-user data is returned (or that suitable "4xx" status is returned for the edge cases where the file-id is invalid, belongs to another user, etc.)

[SwikritiT]

Closing this as the linked PR has been merged #40042