This commit adds the encrypted_data, blinding_point and total_amt_msat
tlvs to the known set of even tlvs for the onion payload. These TLVs
are added in two places (the onion payload and hop struct) because
lnd uses the same set of TLV types for both structs (and they
inherently represent the same thing).
Note: in some places, unit tests intentionally mimic the style
of older tests, so as to be more consistently readable.
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
