fix(core)!: add missing consensus encoding length byte rangeproof & covenants

[sdbondi]

Description

• Adds consensus encode impl for RangeProof and ComSig
• Adds length varint for covenant
• Move version as first encoded byte
• Implement zero alloc hashing for outputs and witness hash
• Limit covenant and tariscript byte size
• Migration to set length byte in existing wallet transactions
• Ensure that an RPC message can never be zero length.
• covenant serde implementation does not use consensus encoding

Motivation and Context

Rangeproof is not fixed size and so requires a length varint.

It is important to ensure that a remote peer cannot cause unbounded allocation, so various length checks are implemented.

The wallet previously only ever stored a 0-byte covenant which is now invalid encoding.

Potential fix for WriteZero, ensuring that all rpc messages are non-zero in length (rare, but possible).

How Has This Been Tested?

Existing tests updated, manually - mined blocks on dibbler

[SWvheerden]

This looks good. Made a comment or two.
We can remove all the places where we split the comsig's and then encode them as this pr now adds an implementation to implement them directly.

I also think we should use consensus encoding everywhere in the hashes and challenges as this is committed to on the blockchain, either in a MMR root, or just straight up in the output/input. And if we want another implementation to be able to verify this it needs to be able to decode/encode it.