ascanrules: Refactor sqli scan rule into helper functions

[FiveOFive]

Overview

Cleaning up sql injection scan rule code ahead of making updates for false positives in zaproxy/zaproxy#8652. This change is just to split the different types of sql injection tests into helper functions. No logic changes. This makes it easier to tell what types of sql injection tests the rule is running and to find the code for each one.

May want to merge these other PRs with unit tests first:

• ascanrules: add SqlInjectionScanRule unit tests for boolean based #5797
• ascanrules: unit tests for error and union based sql injection #5867

Related Issues

• SQL injection false positive on 429 response zaproxy#8652

Checklist

• Update help
• Update changelog
• Run ./gradlew spotlessApply for code formatting
• Write tests
• Check code coverage
• Sign-off commits
• Squash commits
• Use a descriptive title

[FiveOFive]

Fix merged commit and rebased with main. This is just copy/pasting the different types of sql injection logic into helper functions. Unfortunately, the git diff doesn't seem to pick it up the changes as cleanly as it could and it looks messier than it is. Not sure what's up with that.

[thc202]

Needs to ignore whitespace changes: https://github.com/zaproxy/zap-extensions/pull/5868/files?diff=unified&w=1

[thc202]

I think this is changing the behaviour, the returns that would return from the scan method are now just returning from the extracted methods (and flow continues here), I didn't check the whole code yet but at least it should have isStop checks between them.

[FiveOFive]

Good catch. Updated to skip remaining cases if either isStop() of sqlInjectionFoundForUrl

[thc202]

Thank you!

[kingthorin]

🎉
Thank you!!