Websocket Error Handling during websocket upgrade

### What happened?
When an error happens during upgrade of websocket, there's no way to process such error in a custom way.

### What did you expect?
#1975 added possibility to specify handler func for errors, but it gets called only for errors happening at a later stage. It would be nice to get it called during upgrade as well e.g. when Upgrader calls CheckOrigin and origins don't match or when the client hasn't specified correct Sec-Websocket-Version etc

### versions
github.com/99designs/gqlgen@v0.17.20
go1.19.1 darwin/amd64