rename EVMExtraArgsV2 to GenericExtraArgsV2

[RensR]

Renames EVMExtraArgsV2 to GenericExtraArgsV2. This change DOES NOT change the bytecode for any contract except the offchain-helper message_hasher.

[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/early-pumas-design.md

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

[github-actions]

Static analysis results are available

Hey @RensR, you can view Slither reports in the job summary here or download them as artifact here.
Please check them before merging and make sure you have addressed all issues.

[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

[prashantkumar1982]

The old name ClientEVMExtraArgsV2 is still referenced in some tests inside the ccip.ccipevm package.
They too need to change to this new name.