feat(cache): cache event handler stream response

[kerwanp]

🔗 Linked issue

• Cache stream responses #2932

❓ Type of change

• ✨ New feature (a non-breaking change that adds functionality)

📚 Description

Problem

When a stream is used in a cachedEventHandler the cached body is the serialized stream and not the result of this stream.
Resulting in an undesired behavior as the response sent when taken from the cache is the serialized stream.

Solution

This pull request add the ability to use defineCachedEventHandler with stream responses.
When the eventHandler returns a stream, the response of this stream is cached rather than the stream itself.

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[kerwanp]

As I am not aware of all the implications this implementation would have on all the different runtimes, I would be happy to discuss further on how this feature can get merged! @pi0