Emit with latent callback directly in event graph

[getnamo]

Instead of binding to a function we could improve the workflow in some cases by having the callback right there in the event graph context. The ideal use case would be requesting information from server akin to a http GET.

See https://github.com/getnamo/socketio-client-ue4/blob/master/Source/SIOJson/Private/SIOJRequestJSON.cpp#L218 for example C++.

[getnamo]

branch for issue at: https://github.com/getnamo/socketio-client-ue4/tree/graph-latent

[getnamo]

with 5aff141 we have an unstable implementation working for USIOJsonObject for only one hanging latent action.

Requires fixes:

• Use USIOJsonValue
• Unlimited hanging latent actions (some might never use the callback?)

[getnamo]

with 70f6dd1 feature is fully implemented.

Fixed:

• USIOJsonObject -> USIOJsonValue support
• Support for Unlimited hanging pending actions
• Cleanup

Merging to dev-unstable.

[getnamo]

Documentation added at https://github.com/getnamo/socketio-client-ue4/tree/dev-unstable#emit-with-graph-callback

[getnamo]

Released in https://github.com/getnamo/socketio-client-ue4/releases/tag/v1.1.0