Allow migrations with the users did instead of only via the handle

You can login with a user's did via atproto, but PDS MOOver does not take that into account. Add a check if the handle starts with did: to resolve the did doc and use the PDS URL there instead of trying to resolve the handle. Can contact me about an invite code to my dev PDS

https://tangled.org/@baileytownsend.dev/pds-moover/blob/main/src/pdsmoover.js#L68