V0.16.0 graphql ws subscribe

[ChrisABryant]

This change adds graphql-ws support only for subscriptions.

Is backwards compatible so still works with subscription-transport-ws without code changes.

Only difference is in new transport parameter for example:

      const gqlHttpClient = createHttpClient(httpUrl, {
         headers: {
            authorization: 'Bearer ' + token,
         }
      });

      const graphqlWsClient = createClient({
         url: wsUrl,
         connectionParams: {
            jwt: token,
         }
      });

      {
         gqlHttpClient,
         graphqlWsClient // instead of gqlWsClient
      }

[jesse-savary]

Hey @ChrisABryant, I've added your commits into #382 because the development branch is more up to date than main. Please give version 0.17.0 a go and let me know what you think.