Add vulnerability survey request feature flag and SVG image [RUN ALL RSPEC] [RUN AS-IF-FOSS]

What does this MR do?

As part of https://gitlab.com/gitlab-org/gitlab/-/issues/324246/, we will be adding a survey request card to the vulnerability management pages that asks the user to take a survey:

This is the backend work for that feature. It does the following:

1. Adds a vulnerability_management_survey feature flag. The type is ops and disabled by default because while we only want to show the survey temporarily for a few weeks, depending on the feedback we may want to re-enable the survey later down the line to gather more feedback.

2. Adds the path to the SVG icon used in the survey request card.

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 this is ~"feature::maintenance" work to support the actual feature MR here: !56620 (merged)
• [-] 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

Related to #324246