Bitcoin::Crypto release testing data

These files are used by Bitcoin::Crypto for release testing. They come from outside sources:

• taproot.json came from test vectors in BIP341 and is licensed under MIT
• tx_valid.json came from Bitcoin Core test data and is licensed under MIT
• tx_invalid.json came from Bitcoin Core test data and is licensed under MIT
• script_tests.json came from Bitcoin Core test data and is licensed under MIT