get_grid_extents_UTM: Get either of the four grid extents in UTM values
In rich-iannone/PuffR: A set of tools to help with CALPUFF dispersion modelling.

This provides grid extents for a given side of a bounding box depending on how the grid is defined and given a width and height in meters.

1 2	get_grid_extents_UTM(side, lat_lon_grid_loc, UTM_location, domain_width_m, domain_height_m)

`side`	the requested side of the bounding box. Choices are 'left', 'right', 'bottom', or 'top'.
`lat_lon_grid_loc`	the location of the lat/long inputs in relation to the domain. Choices are: 1 (center), 2 (lower left), 3 (lower right), 4 (upper left), 5 (upper right).
`UTM_location`	the UTM location from which the extents will be determined.
`domain_width_m`	the width of the meteorological domain in meters.
`domain_height_m`	the height of the meteorological domain in meters.