Transactions have versions.
Witness programs have versions.
This replaces the transaction digest "version" with an enum. This
will prepare Script and TX for Taproot, which introduces a third TX
serialization format. Also renames sigHash functions in tx.js that had
their own little confusing version numbers:

signatureHashV0 -> signatureHashLegacy
signatureHashV1 -> signatureHashWitnessV0

Taproot introduces a sighash algorithm that requires a serialization
of the values of ALL the input coins into a transaction. Currently,
all the TX check/verify and Script verify methods expect a single
coin to be passed in, to check one specific input at a time. This
commit updates the signature for several functions throughout the
codebase to pass an array of ALL input coins when verifying a TX
input. Legacy behavior is preserved by using the index argument
to pick out the one coin being verified.

Many of the arguments expected by Script.verify() can be found
redundantly in either the tx object or the coins array it is passed.
Therefore the arguments to this function can be greatly simplified:

OLD:
verify(input, witness, output, tx, index, value, flags)

NEW:
verify(tx, index, coins, flags)

This refactor also modifies the worker packets that handle input
checking (async signing will need to be updated as well in a future
commit). All regression tests, bench tests, and script fuzz tests
were checked and pass.

Will be needed to lexicographically compare adjacent merkele
branches in Taproot control block.

Reference from Bitcoin Core src/script/interpreter.h

    // Taproot/Tapscript validation (BIPs 341 & 342)
    //
    SCRIPT_VERIFY_TAPROOT = (1U << 17),

    // Making unknown Taproot leaf versions non-standard
    //
    SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_TAPROOT_VERSION = (1U << 18),

    // Making unknown OP_SUCCESS non-standard
    SCRIPT_VERIFY_DISCOURAGE_OP_SUCCESS = (1U << 19),

    // Making unknown public key versions (in BIP 342 scripts) non-standard
    SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_PUBKEYTYPE = (1U << 20)

Like its caller verify(), this function will need the values of
all the input coins to compute the signature hash for Taproot spends.

Unlike verify(), we don't pull the "output" script from the coin of
the input being checked, because that script may have actually come
from a P2SH redeem script (in the input itself).

This is especially important for Script.isUnknown() which calls
Script.getType(), and will cause TX.hasStandardInputs() to fail
if that type is undefined.

TODO: Address, Witness and Input methods that "guess" their
corresponding output should be checked for interference by new
Taproot witness patterns, and expanded if possible. New functions
in Script/common.js like "isSignatureEncoding()" will need to be
added.

This extends Script.verifyProgram() to cover version 1 (Taproot)
rules. Tests cover standard and mandatory flags (mempool and block,
respectively).

Note at this point only key path spending is fully verified.