[ConfirmBeforeDeletePoint] Ask for confirmation before deleting a point

[TmtStss]

When drawing a perimeter/polygon, ask for confirmation before deleting a point.

In challenging environments, it is a pain to go back to a location to again drop a pin. It happened to me a few times while testing the app (offline mode) in humid rainforests to delete a point 'by mistake' (e.g., pressing the backward button) and have to walk back...

PS: thank you, great work at developing OFG !

[kenstershiro]

@vittorino could you see this feedback from the field? Do you think it's ok to add a confirmation alert on each removal of a polygon point? I can see why it would be important in this type of scenario.