Webpack all the things! Fixes #2135

This significantly speeds up loading of the application; in an average of 3 tests, v1.6
loaded in 11.5s in the runtime on a Mac, whilst the webpacked version of the code
loaded in 5.53s.

web/regression/feature_utils/pgadmin_page.py

@@ -194,6 +194,7 @@ class PgadminPage:
             except (NoSuchElementException, WebDriverException):
                 return False
 
+        time.sleep(1)
         WebDriverWait(self.driver, timeout=self.timeout, poll_frequency=0.01).\
             until(find_codemirror, "Timed out waiting for codemirror to appear").\
             click()