feat(primitives): serialize yParity and v simultaneously

[yash-atreya]

Motivation

Previously, when v was set to 0x0 || 0x1 i.e Parity::Parity(false || true), only yParity would appear in the serialized form of the sig.

Solution

Serialize v along with yParity in that case. Ref: https://github.com/ethereum/go-ethereum/blob/473ee8fc07a3f89cf3978e164a6fad218de9a6b5/internal/ethapi/api.go#L1342-L1345

PR Checklist

• [x] Added Tests
• [ ] Added Documentation
• [x] Breaking changes