Incorrect share identifier for reshares

[rullzer]

See #22285

Basically since we still use the old endpoint (ajax/share.php) to obtain the list of shared info for the current directory we can no longer get reshares correctly. Since that uses the old sharing code that has no idea about how to handle flat reshares.

This means:

1. user1 shares foo with user2
2. user2 shares foo by link

Now user2 does not see the corect share indicator in the webUI.

A possible fix would be to move the listing over to the OCS endpoint now. This is slightly less efficient (more data is transfered). But it is at least complete.

CC: @PVince81 @schiesbn

[rullzer]

PR with start of a solution in #22305

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.