[CCIP-5323] Remove unused operatorforwarder contracts and their associated code.

[pavel-raykov]

Towards https://smartcontract-it.atlassian.net/browse/CCIP-5323

[github-actions]

AER Report: CI Core ran successfully ✅

aer_workflow , commit

AER Report: Operator UI CI ran successfully ✅

aer_workflow , commit

[github-actions]

Solidity Review Jira issue

Hey! We have taken the liberty to link this PR to a Jira issue for Solidity Review.

This is a new feature, that's currently in the pilot phase, so please make sure that the linkage is correct. In a contrary case, please update it manually in JIRA and replace Solidity Review issue key in the changeset file with the correct one.
Please reach out to the Test Tooling team and notify them about any issues you encounter.

Any changes to the Solidity Review Jira issue should be reflected in the changeset file. If you need to update the issue key, please do so manually in the following changeset file: contracts/.changeset/shiny-toys-think.md

This PR has been linked to Solidity Review Jira issue: CCIP-3966

[cl-sonarqube-production]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube

[jmank88]

I am surprised that this one is unused. Are we sure that it is dead? It may have just been delayed.

[pavel-raykov]

I am surprised that this one is unused. Are we sure that it is dead? It may have just been delayed.

the files were added ~ 1 year ago and are not referenced from any other repository in our org. I would defer to the owners if it is fine to remove them.