This commit was previously split into the following parts to ease
review:
- 2d746f68: replace imports
- 4008f0fd: use ecdsa.Signature
- 849e33d1: remove btcec.S256()
- b8f6ebbd: use v2 library correctly
- fa80bca9: bump go modules
This fixeslightninglabs/loop#437 by adding all accounts that are used
in liquidity products such as Loop or Pool. Since both of these products
use key families below 255, we can get by with that number.
The alternative to creating way too many accounts (which increases the
default wallet size by ~250kB) would be to hard code the exact accounts
used by Loop (99) and Pool (210). But that sounds like a bad idea given
that there could always be more accounts being added to those (or other)
products. By making sure the first 255 accounts exist, we have a lot
more flexibility in those products for choosing key families.
With the remote signing instance now not needing to know anything about
addresses or current derivation indices, we don't need to forward any
such calls to that instance and can simplify the RPCKeyRing
considerably.
