Verifies fetch() is blocked by CSP in isolated world and can be cleared
Creating isolated world with CSP...
Fetch result (with CSP): FAILED: TypeError: Failed to fetch
Re-creating isolated world without CSP (should clear it)...
Context IDs match: true
Fetch result (after clearing CSP, same document): FAILED: TypeError: Failed to fetch
Navigating and re-creating without CSP...
Fetch result (after clearing CSP, new document): SUCCESS