Improve communication of which websites are tested by OONI Probe

[agrabeli]

During the OONI Partner Training, participants mentioned that when they run OONI Probe, they don't know which websites they are testing, nor what those websites are about (though we do link to the Citizen Lab test lists in the app).

Participants also highlighted that it's unclear to them if they're testing the URLs in the Citizen Lab global test list, or country test list, or both.

This highlights that we need to improve how we communicate which websites are tested. Perhaps this could be addressed from a UX perspective, or in terms of copy, or both.

This is related to #1935.

[hellais]

It came out during a meeting that the core issue is that people don't understand why certain sites are being tested.

We can perhaps address this with some better copy:

Every time you tap Run, you test different websites that are globally and regionally relevant. You can contribute to what is tested via the test-lists submission interface.

[agrabeli]

I have opened a ticket about editing the copy in the Websites card here: #2072