(APIGatewayv2.websocket: add support for HTTP integration

[cloudshiftchris]

Describe the feature

Presently the WebSocketApi construct supports lambda, AWS and Mock integrations; add support for HTTP integration; effectively all available options in the GUI/CFN for this (proxy, vpc link, etc).

Use Case

Websocket messages being delivered to internal HTTP endpoints.

Proposed Solution

Add a new WebSocketHttpIntegration implementation of WebSocketIntegration

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

CDK version used

2.132.0

Environment details (OS name and version, etc.)

MacOS

[nmussy]

Associated documentation/API:

• AWS::ApiGatewayV2::Integration
• Setting up a WebSocket API integration request in API Gateway
• Might need to take a look at Set up route responses for a WebSocket API in API Gateway as well

Current CDK implementation:

• Docs
• WebSocketIntegrationType

Both WebSocketIntegrationType.HTTP and WebSocketIntegrationType.HTTP_PROXY are currently missing, as well as their associated WebSocketRouteIntegration implementations

[pahud]

@cloudshiftchris Thank you for the report.

@nmussy Thank you for your PR! This is awesome!

[nmussy]

The PR I've opened doesn't address this specific issue, but will add properties that are also used by the HTTP integrations. I'll take care of them later if no one else takes them on 👍