Write browser test as seen in the ticket
Including all support files.
Expectation is that the browser test runs without errors, with the new test failing.
This tasks includes comming up with a naming scheme for the HTML elements under test.
Suggestion is something like "wikibase-lexeme-…".
Decision: never use IDs in HTML, only class names.
Acceptance criteria is as follows: If I comment out the failing browser test line, the next should fail with a useful error message. And so on. If all are commented out, the test should succeed (with being empty).