Switch all tests to use the shared config file. Use a shared method for getting
the extension ID, so we can also test the pageAction popup in the content tests.
Use config data in the background and content scripts for the remaning items, to
not have any hard-coded data in the tests.
Create a new quicktext for the content test, and use it for testing the
autocomplete functionlity, instead of the previously hard-coded default
quicktexts.
Improvements in the content script, to wait for the element that we're sending
keys to, to make sure the tests are not failing because of random `element not visible`
errors.