HDWallet: use assert.throws
HDWallet: moves fromBuffer tests to data driven style
HDWallet: remove unused imports
HDWallet: remove getKeyVersion
HDWallet: use new constructor
HDWallet: remove repeated assertion
HDWallet: extract BIP32 params search function
HDWallet: adds PubKey validation
HDWallet: more explicit branch for parentFingerprint
HDWallet: improve testing coverage
HDWallet: fix test data descriptions
HDWallet: consistent test data ordering

Also adds network parameter for later moving the network specific tests
to be data driven.
HDWallet: add to/fromHex tests
HDWallet: remove unnecessary Base58 context on fromBuffer tests
HDWallet: rename local priv to isPrivate
HDWallet: moves hardened info to test data more explicitly
HDWallet: adds Public -> public tests
HDWallet: rename derivePrivate to deriveHardened
HDWallet: move toBase58
HDWallet: now export all information by default