POC: Use modal dialog instead of notification when clipboard usage fails

[fregante]

Not fully tested, ignore for now

What does this PR do?

• Might fix Copy to Clipboard focus issue in MV3 Side Panel #7324
• Groundwork for Deal with user gesture limitations (permissions.request(), sidePanel.open()) #7327 (comment)

Discussion

This has the potential for solving a few issues:

• BUG: "click anywhere to copy" triggers a page navigation if the user clicks on a link
• UX: "clicking in a random place to copy something is a really out-of-the-ordinary pattern"
  • Deal with user gesture limitations (permissions.request(), sidePanel.open()) #7327 (comment)
• BUG: I think, two clicks are required to activate the "click anywhere to copy" from the sidePanel
  • Copy to Clipboard focus issue in MV3 Side Panel #7324

Checklist

• Add tests
• New files added to src/tsconfig.strictNullChecks.json (if possible)
• Designate a primary reviewer