test: containerized Chrome end-to-end harness that drives the real popup (closes #181)

Runs the real popup in a pinned containerized Chrome and fails on any uncaught
page error or console.error. Also fixes the two defects it caught: the missing
showView import in addToken.js and the missing addressDotHtml import in
transactionDetail.js.

closes #150
closes #151

src/popup/views/addToken.js

@@ -1,4 +1,4 @@
-const { $, showFlash, goBack } = require("./helpers");
+const { $, showView, showFlash, goBack } = require("./helpers");
 const { getTopTokens } = require("../../shared/tokenList");
 const { state, saveState } = require("../../shared/state");
 const { lookupTokenInfo } = require("../../shared/balances");