Add an area/polygon to spatial data

Usage

make_spat_area(spat, project, coord, spat.id, new.id, combine)

spat: Spatial dataset to add polygon too.
project: Name of project.
coord: Longitude and latitude coordinates forming a polygon. Can be a numeric vector of even length or a numeric matrix with two columns.
spat.id: The ID column in spat
new.id: The ID for new polygon.
combine: Whether to use combine_zone. This will turn the intersections between poly and spat into new polygons. Note that the new polygon IDs will be derived from spat and new.id will not be used.

Adds an area/polygone to a spatial area