Add relme verification

Allow OPs to set up rel="me" verification for their user IDs, meaning that when they post a session/thread which links to their website, gamedate shows users that the OP has verified they have control over the content on that page. this could be implemented as a link in the session header with a checkmark next to it. on hover, there could be a tooltip with, for example: "The OP has verified they have control of the content on the linked page" https://en.wikipedia.org/wiki/Digital_identity#Rel="me"_verification https://microformats.org/wiki/rel-me