Enrich POI cross checking information with block data, call cache, entity changes

[neysofu]

This requires persisting all necessary information to the database and modifying GraphQL query results.

See:

• GraphQL route for dumping entity changes in subgraph and block graphprotocol/graph-node#3275
• Add GraphQL route for fetching block data graphprotocol/graph-node#3321
• GraphQL route to expose call cache contents by block graphprotocol/graph-node#3343

[azf20]

@neysofu is there outstanding work required here on Graphix?

[neysofu]

Quite so, yes. This information won't be fetched by default, but will be available upon users' request when they wish to investigate POI divergences. @leoyvens and I will work on this as soon as we've laid some of the foundations that we need.