Update TDAC step and global threshold init values.
Detect pixels which are too noisy to be tuned.

Warning: I started playing with extra (dynamic) attributes of the Pixel class.
Refine noisy pixel behavior.
Move parts of tune algorithm into private methods.
Factor out common behavior to yes-hit and no-hit.

Such as getting hit_pixels.
Fix bug regarding `args` variable.
Tweak default scan parameters.
Add differential update to pixel TDAC updates.

Biggest effect on `_apply_pixel_TDAC_to_chip`, by making it much faster.

NOT TESTED YET.