High Level Read Receipt Tests

Tips for writing these tests:

Break up your tests into the smallest test case possible. The purpose of these tests is to understand hard-to-find bugs, so small tests are necessary. We know that Playwright recommends combining tests together for performance, but that will frustrate our goals here. (We will need to find a different way to reduce CI time.)
Try to assert something after every action, to make sure it has completed. E.g.: markAsRead(room2); assertRead(room2); You should especially follow this rule if you are jumping to a different room or similar straight afterward.
Use assertStillRead() if you are asserting something is read when it was also read before. This waits a little while to make sure you're not getting a false positive.