Refactor invite links

[Velua]

Invite links are too long and lack context when being sent around in Slack / other instant messaging.

Add Identifier

At the the moment the URL is structured as app.chain/?token=token as it's purely a query param the server does not receive this info.
Update the link so it's structed as app.chain/token_id?token=token then using the token_id determine the sender and other context to form into a link preview and inject in meta tags for the senders site.

[swatanabe]

At the the moment the URL is structured as app.chain/?token=token as it's purely a query param the server does not receive this info.

What? query params are sent to the server.