Add evaluation helpers (#33)

* Add evaluation helpers

* Make some helpers only available server-side

They don't make any sense on the client side.

* Fork the right thing

packages/protocol/src/index.ts

@@ -1,4 +1,4 @@
 export * from "./browser/client";
-export * from "./browser/evaluate";
 export * from "./common/connection";
+export * from "./common/helpers";
 export * from "./common/util";