Combine "capture location" and "drop pin" tasks

The idea is that the capture location and drop pin tasks would be combined into a single "Add a point" task, with an option set by the organizer to "Capture data collector's GPS location" or "Allow data collectors to use their GPS location or to place a point anywhere on the map"

Details:

* The location lock will be on by default when the task is first opened.
* If `true`, the user can pan the map to disengage location location (current behavior of "Drop pin").
* If `false`, the location lock will be disabled, and the cannot pan/zoom the map (current behavior of "Capture location").
* The tooltip will be the same as it currently is for "Drop pin", but when location lock is on will also show info shown in "Capture location" task.

Related web FR:
https://github.com/google/ground-platform/issues/2173