Update simpletest example for touch "drag-outside" response

[kmatch98]

This is more of a stylistic change to highlight the button response, if you don't think it adds anything, I'm fine cancelling this PR.

Existing code:
When the button is pressed and the touch is dragged outside of the button, the button remains pressed. Only removing the touch from the screen will reset the button.

New code:
The button is cleared if the touch is dragged outside the button.

Minor edits:
Also, I had to clean up some doc-string pylint errors in the examples, and I made one update to use the pre-defined BUTTON_LABEL variable.

[kmatch98]

Ok, the new pylint fixes have been implemented (for "duplicate code") and this is now passing. It's now ready for review.

[jposada202020]

@kmatch98 I stumble upon this in making my color "styles" new library research, I will be able to make a review when my new hardware arrives later this week. Thanks,

[jposada202020]

@kmatch98 Thanks for this. I tested this using

Adafruit CircuitPython 6.2.0-beta.4 on 2021-03-18; Adafruit PyPortal Titano with samd51j20

Works as mentioned in this PR. Not related with this PR, but an improvement that we could do these examples, the display width and height are hard-coded to 320/240, so we could use the display.width, and display.height value, this will allow for using the same code in different display. let me know if you could do it before we merge these changes. If not I can submit a new PR for this. :)
Thanks again

[FoamyGuy]

Looks good to me. Tested on PyPortal.

Thanks for this improvement and clarifying comments @kmatch98. Thanks for testing @jposada202020. We can make a new PR for using dynamic display sizing in the examples.