[Feat] Allow creating a DB entry by double-clicking on the map

[ghost]

The idea is to allow creating a DB entry by double-clicking on the map, automatically filling in the Lat. and Lon. This feature should work for new gas station entries too.

[ghost]

In the Form "Reportar Posto de Combustível em Falta" the "Add info" option is not very intuitive. To indicate the location it should be possible to choose a point on the map. Should not be necessary to fill in fields that can be acquired by map geoprocessing tools.