fix: report errors thrown after the frame is ready

Certain challenges involve code that is not run until the user
interacts with the preview (typically via a click listener). This uses
consoleProxy to report those errors.

Error logging has been simplified, reducing the number of places errors
can be reported from.

Some of the redux-saga code has been renamed in an attempt to improve
clarity.

client/src/templates/Challenges/redux/index.js

@@ -330,9 +330,8 @@ export const reducer = handleActions(
       isBuildEnabled: true,
       isCodeLocked: false
     }),
-    [types.disableBuildOnError]: (state, { payload }) => ({
+    [types.disableBuildOnError]: state => ({
       ...state,
-      consoleOut: state.consoleOut + ' \n' + payload,
       isBuildEnabled: false
     }),