fix(core)!: include issuer public key in contract id hash

[sdbondi]

Description

• includes issuer public key and commitment in contract hash
• update command "wizard" code to fetch contract id from resulting transaction
• simplify FixedString code
• removes unused Hashable trait impls

Motivation and Context

The contract ID should be a hash of all contract definition data. Adding the commitment allows contracts with the same name label to exist on the blockchain at the same time.
The contract name functions as a label and does not have to be globally unique. This PR essentially makes the
<issuer_pk, contract_name> pair unique.

How Has This Been Tested?

Existing tests, manually

[SWvheerden]

I have my questions in allowing duplicate contracts.
If this is all the same:

contract_name
contract_issuer
contract_spec

Is it not essentially the same asset, just with a different owner? Do we want to allow this? I am thinking no, why do we want to allow copes of an asset to existing? If you change the name or the spec, it's going to be unique?

Another question I have is, is the contract def UTXO always going to stay static and never change? If it is, it kinda becomes hard to validate contract_id

[sdbondi]

@SWvheerden There are a few ways to do this, but I dont think we want to tie the contract_id just to the contract_name as that functions as more of a label. This PR is more about tying the contract to a specific UTXO. i.e. you publish a contract utxo and you get a new unique contract_id on-chain. Also removing the need for the issuer to generate a new public key if a contract with the same "label" (contract_name) is used. However, the issuer generating a new key is not unreasonable.

I think I will change the PR to only include the definition UTXO data for now as that is not controversial.