feat(cloudflare): Add support for durable objects

[AbhiPrasad]

This PR introduces a new instrumentDurableObjectWithSentry method to the SDK, which instruments durable objects. We capture both traces and errors automatically.

Usage:

class MyDurableObjectBase extends DurableObject<Env> {
 // impl
}

// Export your named class as defined in your wrangler config
export const MyDurableObject = Sentry.instrumentDurableObjectWithSentry(
        // need to define options again because durable objects can be in a separate instance
        // to the cloudflare worker 
	(env) => ({
		dsn: env.SENTRY_DSN,
		tracesSampleRate: 1.0,
	}),
	MyDurableObjectBase,
);

This should work with websockets, and thus https://github.com/getsentry/sentry-mcp as well.

This PR also refactors some types in packages/cloudflare/src/handler.ts with the withSentry method, which should prevent type errors in some situations. This might help with #16099

resolves #15975
resolves https://linear.app/getsentry/issue/JS-285
resolves #16182
resolves https://linear.app/getsentry/issue/JS-398

[Lms24]

I think this is fine for now but since we have stuff like this in multiple sdks, it's probably worth extracting it in the future