* Move block test vectors into separate files
* Refactor block test vectors into their own module
* Remove some duplicate test vector data
* Add mainnet block test vectors for each network upgrade
* Add testnet block test vectors for each network upgrade
* Update the TEST_BLOCKS list
* Add basic tests using TEST_BLOCKS
* Ignore shell.nix
* add proptests for invalid forms of input
* apply proptests to each valid block we have
* start moving equihash logic to BlockHeader
* provide an error based interface
* cleanup logging in dependent crate
* use is_equihash_solution_valid everywhere
* switch to proper equihash crate branch
* add block size limit test
* calculate max_transactions_in_block and max_inputs_in_tx
* abstract block generation
* move all test vectors to zebra-test