Link bid and reveal

[nodech]

Goals for this PR:

• Closes: https://github.com/handshake-org/hsd/issues/716.

Tasks

• [x] Add height to the bid.
• [x] Add bid prevout to the reveal.
• [x] Add extra index in db for bid -> reveal.
• [X] Implement migration

NOTE: Not-owned migrated bid and reveals wont have the links, as TX records necessary for it are not recorded. They will instead default to nulls (-1 for bid height, Null Outpoint for reveal). In order to fix this issue, rescan the wallet.

This allows us to do minor release for new APIs that can utilize linked entries for various means. Currently, this does not add API endpoints. Ideally, these APIs will be implemented with #892

[coveralls]

coverage: 68.583% (+0.03%) from 68.55% when pulling e6144b05a2f0b11c2707c1d8a2cb7c15ce43df8d on nodech:update-bidreveal-entries into 509ffe5f6c3cf8063316ba67534013c93a39ab27 on handshake-org:master.

[coveralls]

coverage: 68.593% (+0.04%) from 68.551% when pulling 5915b31bd5939bf115401c048a841a7d6ee6ce09 on nodech:update-bidreveal-entries into e93bd53e839516dec2fbeab60ad0b7d84e0c4c93 on handshake-org:master.

[coveralls]

coverage: 68.649% (+0.1%) from 68.551% when pulling d566bb26db64276dbe40238d777733427692a3f3 on nodech:update-bidreveal-entries into 106fbfaacf4f154ee0e81712409b907c621f6e74 on handshake-org:master.

[coveralls]

coverage: 68.659% (+0.1%) from 68.551% when pulling 14019d1841f84e9f473a20cf7d8813844abda0a0 on nodech:update-bidreveal-entries into 106fbfaacf4f154ee0e81712409b907c621f6e74 on handshake-org:master.