SLIP-39 "Extendable" support; v14.0.2

Support for v14.0.2 is limited to macOS on Apple Silicon.

Implements SLIP-39 "Extendable" mnemonics:

SLIP-39 Mnemonics recover a unique (but "valid") Seed and derived
wallets, no matter what /alternative/ passphrase you use! Your
/original/ Seed can only be recovered with the originally specified
"correct" passphrase.

Extendable SLIP-39 Mnemonics ensures that all SLIP-39 Mnemonic sets
generated from the /original/ Seed and original "correct" passphrase
will /always/ result in the same unique Seed for each /alternative/
passphrase.

Non-Extendable SLIP-39 Mnemonics recover the /original/ Seed with the
"correct" passphrase, but different unique Seeds for all /alternative/
passphrases.

This feature is only relevant if you want (or need) to generate a new set of
SLIP-39 Mnemonic cards from a certain Seed (ie. from a BIP-39 Mnemonic)
-- and you want all of the "alternative" passwords to generate the same
accounts as the original SLIP-39 Mnemonics yielded.

Since we don't recommend you use SLIP-39 passwords at all (since they
are not well supported an Hardware Wallet devices), this "Extendable" support
is not likely relevant to you.