parallell workflow with virtualspecies package

[wlangera]

gcube could be used in parallel with the virtualspecies package. The difference would be that the input data for virtual species are bioclimatic variables while gcube starts from and empty polygon. There are 3 points where output from virtualspecies can be implemented in gcube:

1. Environmental suitability map into the occurrence process
   • Aggregation function to resample at new resolution
   • Link function (?rescale_suitability_raster()) to transform virtual species suitabiliity map to raster which can be sampled by sample_occurrences_from_raster() in the simulate_occurrences() function
2. Presence-absence map into the detection process
   • Link function (?occurrences_from_raster()) to transform raster to point sf object (centroids)
3. Sampled presence points into the grid designation process
   • Link function (?virtual_occurrences_to_sf()) to transform virtual species object to sf object such that it can be used by add_coordinate_uncertainty() and grid_designation() functions

[wlangera]

@micdimu @rociobeatrizc @MatildeUNIBO I created this issue to work with virtual species. You can focus on the virtualspecies workflow.

Afterwards, I can integrate it within the main gcube functions.