Support for grpc-web without external proxy

[everflux]

It would be nice, if grpc-web would be supported without the requirement of a gateway-proxy.
Related to:

• Built-in support of grpc-web clients grpc/grpc-java#4823
• Add an ability to run protobuf server as a Servlet 4 grpc/grpc-java#1621
• https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-WEB.md

I am unsure if this should be handled by grpc-s-b-s or the java library, I assume the java lib is too low level.

[fieldju]

What is the status of gRPC-web and Springboot?

[jvmlet]

The only embedded Java grpc web proxy implementation I'm aware about is https://github.com/grpc/grpc-web/blob/master/src/connector/README.md This is still WIP and is not published as java artifact so far. Once it's published I'll be more than happy to integrate it as part of this starter.
grpc/grpc-web#686 (comment)