perf: Migrate to new crypto libraries using dalek's math

[sparx7783]

Problem

Go's std lib crypto/ed25519 is not using the optimized ed25519 math used in Dalek's rust lib, which offers significant performance improvements, we can switch to github.com/oasisprotocol/curve25519-voi to get these improvements.

Summary of Changes

Migrate from crypto/ed25519 and filippo.io/edwards25519 to new oasisprotocol/curve25519-voi, with slightly rewriting the isOnCurve verification function for slight api differences. Uses VerifyWithOptions(..., verifyOptionsStdLib) to keep verification 1:1 with the previous stdlib implementation.

Benchmarks

Operation	main (stdlib + filippo)	voi	Speedup
Sign	19,650 ns, 1 alloc	11,420 ns, 1 alloc	1.72×
Verify	37,548 ns, 0 allocs	23,491 ns, 0 allocs	1.60×
IsOnCurve	2,786 ns, 0 allocs	2,519 ns, 0 allocs	1.11×
FindAssociatedTokenAddress (wSOL)	25,157 ns, 58 allocs	23,086 ns, 58 allocs	1.09×

[sonicfromnewyoke]

awesome MR, thanks 🙏