Ingest lists of geohashes or other shapes and convert to multipolygons

[schaunwheeler]

It sometimes may be desireble for a collection of shapes to be treated as a single multipolygon. This could be accomplished by allowing Theto to recognize lists as a collection of items to convert, and then including the functionality for geohashes and points to be converted to multipolygons and multipoints. After that, the rest of the pipeline should work the same.