to do: `calc_zoi_cumulative`

[bniebuhr]

• Document parameters
• implement function within GRASS - r.neighbors and r.resamp.filter
• implement check to see if the input map is binary (or only positive values), and raise an issue if not
• implement CUT extent
• adapt example creating a grass db
• test time for different implementations in GRASS and R (r.resamp.filter, r.mfilter, r.neighbor, terra)
• later: implement Gaussian with parameters based on zoi

[bniebuhr]

Mostly done. Still missing:

• implement function within GRASS - r.neighbors (all) and r.resamp.filter (specific filters)
• implement check to see if the input map is binary (or only positive values), and raise an issue if not - will not be done
• implement CUT extent

[bniebuhr]

Parameter zeroAsNA introduced for R, missing the implementation for GRASS.
Must still check if it is possible to avoid copying the input as r0 <- x to avoid increasing memory usage.