New Gismo components: Green View Index and shapefile reader

Small New Year addition to Gismo's components:

1) Green View Index (GVI)

GVI evaluates visual greenery from pedestrian’s perspective.

An example file can be downloaded from here:
https://github.com/stgeorges/gismo/blob/master/examples/green_view_...

2) Shapefiles (.shp) files reader:
Shapefiles to test the new "read SHP" component:
https://qgis.org/downloads/data/qgis_sample_data.zip  (folder '\qgis_sample_data\shapefiles')

3) Two bug fixes
- "OSM 3D Roads" component now runs on Rhino 7 as well.
- "Bathymetry 1' color palette allowed to be used.

Gismo wishes you happy holidays and Happy New 2021!