Add setCursorPosition.

When source is updated we need to update their values. Also renamed
mX/YCursorPosition to mRawX/YCursorPosition to indicate it stores raw
values (w/o applying offset).

Bug: 134788085
Test: atest libinput_tests
Change-Id: I1533d79a7542291974ff572d3aeaf9924e3f0751