feat: add initialize func to SubnerRegistrator

[JDawg287]

Description

This PR adds an admin parameter for the SubnetRegistrator.sol smart contract via an initialize function.
The rationale is to have a constant address for the SubnetRegistrator.sol smart contract while having access control.

Fixes TP-700

Additions and Changes

• Revert changes in the deploy.ts scripts introduced in chore: add AC for registering/removing subnets #102
• Added a parameter admin in the initialize func of the SubnerRegistrator.sol smart contract
• Added deploy-subnet-registrator.ts script
• Made changes to the register-subnet.ts script to allow the sequencer/validator to register a subnet

PR Checklist:

• I have performed a self-review of my code
• I have commented on my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added or updated tests that comprehensively prove my change is effective or that my feature works