Add touchpad drag-lock related settings

[hanaral]

Problem

The current touchpad mechanism to drag seems like a monolithic, rather inaccessible solution that is only there because it was there before. I know that people who have less dexterous fingers (whether that is a medical condition or age, it shouldn't matter) struggle to double-tap-to-drag.

Proposal

Add options to change the mode of touchpad drag locking such as:

• Double tap to lock the drag until clicked again
• 3 Finger drag (disables ability to use 3 finger workspaces)

This is the way macOS has handled it for a while and it works really well (I much prefer 3 finger dragging as opposed to double tapping)

Prior Art