* dep: upgrade secp256k1 to use btcec/v2 v2.3.2 and update insecurity pkg
* build ci: upgrade go to 1.19 and golangci-lint to 1.50.1
* docs: fix format that does not follow the goimports
* dep: redirect github.com/bnb-chain/tendermint to v0.31.13
* ci: disable GOPROXY
This commit changes the behavior of BitCurve.Add to be more inline
with btcd. It fixes two different bugs:
1) When adding a point at infinity to another point, the other point
should be returned. While this is undefined behavior, it is better
to be more inline with the go standard library.
Thus (0,0) + (a, b) = (a,b)
2) Adding the same point to itself produced the point at infinity.
This is incorrect, now doubleJacobian is used to correctly calculate it.
Thus (a,b) + (a,b) == 2* (a,b) and not (0,0) anymore.
The change also adds a differential fuzzer for Add, testing it against btcd.
Co-authored-by: Felix Lange <fjl@twurst.com>
