Users shouldn't see unrelated members and groups

Currently in v0.21.0 any member can go into workspace settings and see all other members, all pending invites and all groups. At this time, the permissions seem to work correctly only for spaces so that a member can only see spaces where they are added. Although an Owner B can't see any spaces if the first owner didn't add the Owner B to a space - this behaviour is not consistent but might have some benefits. On the other hand if we delete the initial Owner A, it could be that some spaces cannot be edited ever again. I suggest the following implementation. Members: • Members can only see spaces they are part of. • Members can only see groups they are part of. • Members can only see other members when they are part of the same group or space. • Members can only see pending invites when they are part of the same group or space. --- or simpler --- • Members can not see any workspace settings (as they aren't able to change them anyway). Admi…