Improved T-Deck trackball responsiveness

[mean-ui-thread]

From yesterday's PR #273, I realized that there were still couple of issues:

• the accumulated up/down/left right with a value of 1 would get stuck and never reset, leading to an accidental move-then-select issue that PR Resolved T-Deck trackball oversensitity and added Kbd backlight support #273 was supposed to be addressing
• It significantly penalized fast scrolling, especially when quickly switching direction (from left immediately to right, or up vs down, etc)

So I took a different approach, ensuring that

1. We still require 2 ticks of any direction to count toward the movement treshold
2. Swiching direction no longer requires up to 3 ticks when quickly switching directions
3. fast scroll remains quick
4. no movements for 250ms resets the accumulated trackball directions back to zero.

Essentially, it's almost turning the trackball into a joystick, where +1/-1 is essecially a dead-zone, and +2/-2 is accepted, and no movement after 250ms resets the joystick back to the center at 0,0.

Tested locally on my two T-Deck Plus.

[mean-ui-thread]

I noticed that left was positive and right was negative before. Still wondering why left and right were inverted here...

I even checked in LilyGo's T-Deck example code, and left is 1, right is 2:

https://github.com/Xinyuan-LilyGO/T-Deck/blob/651631d789b7aca4378333ece196409078b3f053/examples/LvglArduinoVNC_VGA/TDECK_PINS.h#L31-L32

If you perfer keeping left and right inverted, please let me know. I just changed this to make it more intuitive but it's not a big deal if you prefer left as positive on X