also look in just_pressed touches for position

[mockersf]

Objective

• On some devices, UI buttons are not responsive

Solution

• On device with a slower frame rate, touch event can start and end in the frame rate
• When looking for a touch position, also look into the just_pressed touches that are not cleared by the end event but only at the end of the frame

[NthTensor]

I think this issue will be resolved when the pointer abstraction from mod_picking is up-streamed. Touch pointer entities are inserted in First and removed in Last, so position data for each touch always lasts at-least one frame.