Add Cloudflare Integration tests

[timfish]

Description

• Ref test(cloudflare): Add integration test infrastructure #16848

We should add tests for the following and we should test errors and tracing:

• Basic fetch
• fetch with trace propagation
• scheduled - I think there's a way to trigger this via wrangler?
• email?
• queue
• tail
• onError & errorHandler
• Durable Objects
• Workflows
• D1
• Tests for individual frameworks running on Cloudflare?