Fix mapcanvas UX issues

[tomasMizera]

Update, ready for review

These things are fixed/added:

• The formula for calculating vector distance was missing + 🤦🏻‍♂️ 😃 , resulting in wrong distances calculated when you dragged the map vertically
• Added distance threshold for double clicks - now the second click must be within a threshold from the first point.
• Added time elapsed threshold for detecting drag movement - sometimes, if you move a map just by a tiny bit to fit the point, you might not exceed the distance threshold to detect the movement as a drag. It would be detected as a simple tap. This caused unexpected actions while recording new/updating existing geometries. Now to detect the drag gesture we use a combination of a distance threshold and a time threshold ("how long the tap lasted")
• Thresholds are now read from Qt built-in Application.styleHints.xyz

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• Added distance threshold for double clicks
• Make the drag.threshold smaller when digitizing -> when a user is digitizing, they need to pan the map by small distances that sometimes do not meet the drag.threshold. We need to find a better threshold and test it on all platforms.

[PeterPetrik]

Tested iOS and it works nicely