Should shapes be exploded into individual Polygons?

[irm-codebase]

Is your feature request related to a problem? Please describe.
I've noticed that often we want to eliminate certain bits from shapefiles.
These can be islands, some oddball region, etc.

This is near-impossible to filter if the shapefile itself is a multipolygon.

Describe the solution you'd like
So, the proposal is to:

1. Ensure each element in the final shape file is a simple corrected Polygon, even when requesting NUTS0 or country aggregation.
2. Add some specific identifier to these exploded regions.
3. Add an option to remove specific IDs in the configuration. If found, it is removed.

Implementing this should be straight forward.

[brynpickering]

Often, I find that I am OK with multipolygons if they truly represent large enough distinct areas in a country but that I don't want tiny islands or what amounts to random noise around the edges. I usually set a configurable filter that allows me to strip out polygons from within a multipolygon that are either less than X km2 or Y % of total area.

[irm-codebase]

Thanks for the suggestion @brynpickering

Yeah, this seems like a good idea. We could even set this up in a similar way to other settings: a default internal setting (likely setting this 'off'), a global setting on the user-side, and per-country overwrites.

Then this can go in the per-country harmonisation step, likely before Voronoi is run.