Wrapper show method improvements

[asinghvi17]

• Show crs only on the top level geometry, not sub geometries
• Show extent, if calculated, only on the top level geometry (?)
• Compact CRS if possible, if convertible to EPSG then show the EPSG for instance. If not then show a short preview of the string.

[rafaqz]

Convertible to EPSG needs GDAL or Proj...