Separate validation out of site profile creation - On-demand DAST scans profile selectors

• Parent epic: &4871 (closed)

Implementation plan

• In ee/app/helpers/projects/on_demand_scans_helper.rb, update the Projects::OnDemandScansHelper#on_demand_scans_data method to include a link to the docs about site validation.
• The selected profile's label in the dropdown should be suffixed with:
  • (Active) or (Passive) for scanner profiles.
  • (Validated) or (Non Validated) for site profiles.
• When a non-validated site profile (validationStatus) is selected along with an active scanner profile (scanType):
  • Form submission is disabled.
  • Show an alert which includes the aforementioned link to the docs.
  • In the scanner profile's summary, the scan type is displayed in red.
  • In the site profile's summary, the validation status is displayed in red.
• Specs
  • ee/spec/frontend/on_demand_scans/components/profile_selector/scanner_profile_selector_spec.js
    • (Active scan) suffixed to dropdown labels when appropriate.
  • ee/spec/frontend/on_demand_scans/components/profile_selector/site_profile_selector_spec.js
    • (Not validated) suffixed to dropdown labels when appropriate.
    • In the summary, target site is red and includes (Not validated)
  • ee/spec/frontend/on_demand_scans/components/on_demand_scans_form_spec.js
    • When conflicting profiles are selected:
      • Alert rendered.
        • Includes link to the docs.
      • Submit button disabled.