ghverify

This realm is intended to enable off chain gno address to github handle verification. The steps are as follows:

• A user calls RequestVerification and provides a github handle. This creates a new static oracle feed.
• An off-chain agent controlled by the owner of this realm requests current feeds using the GnorkleEntrypoint function and provides a message of "request"
• The agent receives the task information that includes the github handle and the gno address. It performs the verification step by checking whether this github user has the address in a github repository it controls.
• The agent publishes the result of the verification by calling GnorkleEntrypoint with a message structured like: "ingest,<task id>,<verification status>". The verification status is OK if verification succeeded and any other value if it failed.
• The oracle feed's ingester processes the verification and the handle to address mapping is written to the avl trees that exist as ghverify realm variables.