Webconsole is a dependancy for the conversion of AddonActor

Note: AddonConsole inherits from this actor, there will be some clean up there once this is updated

We also need to address refactoring evaluateJSAsync, as it is currently a synchronous function. Several older actors are relying on it so this needs to be done with care. New actors can return promises, but evaluateJSAsync breaks if it is turned into one. what needs to be done once protocol.js is introduced is that we modernize this function, and make sure that the tests are passing. here is a try run with the failing tests: https://treeherder.mozilla.org/#/jobs?repo=try&revision=f6d34f4f03a85b601745d641625d29a8e0cd316a

Pushed by nchevobbe@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/5cba74a67e19 Convert WebConsoleActor to protocoljs Actor. r=nchevobbe,yulia

Pushed by nchevobbe@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/7a2f71c2dfd2 Clean up WebConsoleActor events and responses. r=nchevobbe