Add a new route `dast_scans` in Security Configuration

Related #324583 (closed)

What does this MR do?

This adds a new route dast_scans which is a clone of dast_profiles route.

This is the first steps towards renaming /dast_profiles => /dast_scans in Security Configuration

Next steps

• Update links via !56966 (merged) after this MR is merged and deployed to production

Screenshots (strongly suggested)

No visual changes

How to test this

Navigate to the DAST profile library page in your GDK:

/:namespace/:project/-/security/configuration/dast_scans

It should behave same

/:namespace/:project/-/security/configuration/dast_profiles

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because it doesn't update any existing links
• Documentation (if required)
• Code review guidelines
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• Style guides
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• 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