Add an option to store GPS coordinates of the editing user

[rpispico]

As an option save the GPS coordinates if the same is active.

During a field survey it will be possible to know the coordinates from where the feature was inserted/modified.

[volterra79]

@rpispico can you explain the flow better?

[rpispico]

It would be useful to have the GPS coordinates saved (as an option like creator user and modifier user) in a field.
These are the coordinates of the GPS location when the user saves the edit.

If GPS off (or editing done from PC) the field will be empty

[Raruto]

Moved into the g3w-client-plugin-editing repository