ascanrules: Path Traversal add details for dir match Alerts & reduce FPs

[kingthorin]

Overview

• CHANGELOG > Added change note.
• Message.properties > Added key/value pair supporting the new Alert details.
• PathTraversalScanRule > Updated to include Other Info on Alerts when applicable, and pre-check the original message response to reduce false positives.
• PathTraversalScanRuleUnitTest > Updated to assert Other Info or lack thereof where applicable, also assure appropriate skipping due to pre-conditions.

Related Issues

• Fixes zaproxy/zaproxy#8379

Checklist

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