Make available artifacts path in test request

[mnovait]

During the execution playwright produces different artifacts such as screenshots, videos or traces. Some of them are already save and made available in the class ArtifactsRecorder. I've created this PR to standardize how the plugin saves the paths as class attribute (videos were missing) and to copy in the test request the final result. The final goal is to have them in the test request, so they can be, for instance, used in the test report or somewhere else in the test flow.

Yes, but we usually start with an issue/feature-request, explain the use-case, elaborate on workarounds etc. Do you mind filing a feature request?

Originally posted by @mxschmitt in https://github.com/microsoft/playwright-pytest/issues/241#issuecomment-2388562443