Use enriched ID type in on-demand scan create mutation

What does this MR do?

this merge requests converts the backend and frontend requests for creating an on-demand scan over to use an enriched id type.

How to test this?

• enable both feature flags.

echo "Feature.enable(:security_on_demand_scans_feature_flag)" | bundle exec rails c
echo "Feature.enable(:security_on_demand_scans_site_profiles_feature_flag)" | bundle exec rails c

• visit a project's on-demand scan form: /:group/:project/-/on_demand_scans/.

Conformity

• [-] Changelog entry not needed as this is behind a feature flag
• [-] 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