Normalize DAST location path for stability

What does this MR do?

Makes changes to help improve the stability of DAST results over multiple scans. Changes are:

• Remove the query string from the path, i.e. normalizes /my/path?search=houses to /my/path
• Remove the end slash from the path, i.e. normalizes /my/path/ to /my/path
• Remove the fragment from the path, i.e. normalizes /my/path#search to /my/path

These changes will affect the way de-deduplicating of DAST vulnerabilities occurs on the Security Dashboard, as the same vulnerability found at the same location (including path) are considered the same vulnerability.

This MR has the potential to remove duplicate findings. For sites that show different pages/content depending on the query string/fragment/end slash, the Security Dashboard will hide vulnerabilities for that content (i.e. False Negative).

This resolves issue #212635 (closed).

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team