Create Confirmation Dialog for Admin Tools Scans

[chrtorres]

🗣 Description

• Created pop up dialog to confirm launching a scan.

💭 Motivation and context

Prior to this improvement, a user would launch a scan without a confirmation step to avoid running a scan mistakenly. This implementation leads to poor user experience. With this improvement, a confirmation dialog appears when a user attempts to launch a scan.

This closes issue #93 and CRASM-263

📷 Screenshots (if appropriate)

✅ Pre-approval checklist

• [x] This PR has an informative and human-readable title.
• [x] Changes are limited to a single goal - eschew scope creep!
• [x] All future TODOs are captured in issues, which are referenced in code comments.
• [x] All relevant type-of-change labels have been added.
• [x] I have read the CONTRIBUTING document.
• [x] These code changes follow cisagov code standards.
• [x] All relevant repo and/or project documentation has been updated to reflect the changes in this PR.
• [ ] Tests have been added and/or modified to cover the changes in this PR.
• [ ] All new and existing tests pass.

✅ Pre-merge checklist

• [ ] Revert dependencies to default branches.
• [ ] Finalize version.

✅ Post-merge checklist

• [ ] Create a release.