[Bug] Disallow grafts that are within the reorg threshold of the base subgraph

[leoyvens]

Bug report

Currently this is allowed, but if the base subgraph reverts it can result in an inconsistent graft. This should be instead rejected at deployment time.

Relevant log output

2024-01-02T14:22:30.164887291Z stderr F Jan 02 14:22:30.164 WARN Firehose selected first streamed block's parent should match subgraph start block, reverting to last know final chain segment, firehose_start_block: #18746373 (5ca99c16915d2cd025e4fc1b3962c08eb75d171840d70116d2ff9204d3a1c5cc), subgraph_current_block: #18746373 (ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff), provider: mainnet-firehose-sf, deployment: QmXYAmabbEmnSDNR5GWJhmm2NQKXnPkSJEBC3EsMwjXr4e, sgd: 567032, subgraph_id: QmXYAmabbEmnSDNR5GWJhmm2NQKXnPkSJEBC3EsMwjXr4e, component: FirehoseBlockStream

2024-01-02T14:22:30.772869846Z stderr F Jan 02 14:22:30.772 INFO Reverting block to get back to main chain, revert_to_ptr: #18746174 (b6fc3f8b01773770b6b4e90c691df73d8baea33b49cbf49b0adffa6936d13367), subgraph_ptr: #18746373 (ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff), sgd: 567032, subgraph_id: QmXYAmabbEmnSDNR5GWJhmm2NQKXnPkSJEBC3EsMwjXr4e, component: SubgraphInstanceManager