Update spatial libraries

[klr324]

Many spatial libraries are being archived in cran. The library sp has not been archived, but it is recommended to migrate from using this library to terra, stars, or sf.

Most of the in house functions can be tranferred to terra, however, the functions using the spacetime library cannot. The library spacetime depends on sp.

[klr324]

The maintainer of spacetime has suggested a more modern take on can be found in https://r-spatial.org/book/13-Geostatistics.html (see discussion: edzer/spacetime#44)

This update uses gstat, sf, and stars. sf and stars are among the recommended spatial libraries to migrate to.