Make mailbox search include search of alias strings

[marcusquinn]

This:

Help me find what aliases I've added and where or not.

[girish]

I was hoping someone will point this out before I implement it

[marcusquinn]

Looking forward to domain aliases for mailboxes. That's pretty much the only thing left we use GSuite for, so looking forward to migrating away from that.

[nebulon]

I've added a task in gitlab for this now at https://git.cloudron.io/cloudron/box/-/issues/738