Test Assertions 3.1, 3.2

These are basically just copies of the `pointerevent_pointermove_*` files with updates to test `pointerup` instead of `pointermove`.
The "&& event.pointerId == pointerdown_event.pointerId" part is not necessary, as it is being tested in an assertion below (as it should be).
(The same applies to the equivalent pointermove test.)