feature grid functionality : copying and pasting features

[mdelsinne44]

Description

New feature grid functionality allowing entities to be copied from one layer to another, for example, from entities in a locally loaded shapefile to a WFS layer. It will be necessary to enable editing mode on the layer where the entities will be copied. The geometry, as well as all attributes that have a corresponding field in the target layer, will be copied

Other useful information

The functionality stores the information in JSON format in the local storage.