Create profile selector component

• Related issue: #246780 (closed)

What does this MR do?

This creates the OnDemandScansProfileSelector component. It will serve as a way to dynamically render the Site profile and Scanner profile selectors in the On-demand scans form.

Currently, both those selectors are implemented individually in the form, which results in a bloated template and a lot of duplicated code. Creating this new component lets us bundle the shared code in a single component that we'll include in the form in a follow-up MR where we'll cleanup the duplicated bits.

Screenshots

Since the component currently isn't used anywhere, there aren't any relevant screenshots to put here.

For reference though, here are the selectors that are being reimplemented in this new component:

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry (no changelog needed as those are backstage changes)
• [-] 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