Update APIGatewayProxyRequest for the new WebSocket Fields

[normj]

The APIGatewayProxyRequest event class needs to be updated to support the new properties for WebSockets like DomainName and ConnectionId.

[normj]

Feature merged into dev branch to go out next release.

[diegosasw]

@normj do you have any example on how a json event from API Gateway websocket looks like?

I'm wondering whether I should be able to use CURL to post some json to my lambda running on a local AWS Runtime Interface Emulator pretending that it's coming from a websocket, since SAM does not support websockets and I can't test that integration locally.

Is this a good example and the only difference from a REST api event is that it includes connection id and domain?
https://github.com/FranciscoJCLus/aws-lambda-dotnet/blob/61e096a38ca67947bdc220d1dddfd142a3764f47/Libraries/test/EventsTests/proxy-event.json