Setup an environment to perform end to end tests using the cypress Test Runner.
Before running the tests, Software Heritage web application is executed in the
background using in-memory storages for fetching data contained in a sample archive.
To easily run the tests, two new make targets have been added:
- `test-frontend`: Run tests in headless mode (this should be used in a CI environment)
- `test-frontend-ui`: Run tests using the cypress GUI
As an example, a couple of tests regarding the highlighting of lines of code have been added.
Related T1768