Make default derivation path BIP-44 compatible, 44/145/0'/0'

NB: Jonathan and Tom are arguing over this, not yet sure what's the truth. Needs independent assessment. Some debate around which is correct, but the problem is solved either way once we have scanning of both paths.

Use 44/145/0/0 instead of 44/0/0

We will need to announce to existing users to move their coins across and/or detect the current derivation path from wallet when scanning.

https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki

https://github.com/satoshilabs/slips/blob/master/slip-0044.md

See related ticket #21 (closed)

Also, upgrade to add support for 24 word seed phrases (with either / both derivation path styles), for example like the ones generated in Stacks Wallet (??)