Swipe and hold action.

[Megalomaniak]

We have a swipe action, we have a tap action. They can't be combined to work as a '[swipe to] and then [hold at coordinate] until [trigger release]' action. So maybe a new action type can work instead?

Developer TODO (don't remove)

• create new branch. put issue number at start of name
• update documentation
• merge and delete branch (don't squash because want commit history to see why I made changes)