chore: progressively migrate webpack test case

[IWANABETHATGUY]

Related issue (if exists)

Closed #3116

Summary

Here is an example,
before

I changewebpack-test/configCases/assets/delete-asset/test.filter.js to:

-module.exports = () => {return false}
+module.exports = () => {return -1}

after

🤖 Generated by Copilot at 9cf6469

This pull request updates the webpack test cases and the compatibility report for rspack, and adds documentation on how to migrate and filter test cases. It also introduces a new formula for measuring the compatibility of rspack with webpack.

Walkthrough

🤖 Generated by Copilot at 9cf6469

• Add a section to the README file that explains the migration strategy and compatibility formula for webpack test cases (link)