BIP54: Consensus Cleanup test vectors

This introduces test vectors for BIP54. There is one set of vectors per each of the 4 mitigations. The vectors were generated using the BIP54 implementation against Bitcoin Inquisition available [here](https://github.com/bitcoin-inquisition/bitcoin/pull/99), as well as a custom miner as a Bitcoin Core unit test available [here](https://github.com/darosior/bitcoin/commits/bip54_miner/). Documentation is provided with more details about each set of test vectors and describing how to use them.

Specification