Add a top level function to save snapshots to disk

[jadeallenx]

Problem to solve: Callers currently have to choose whether they want to store a compressed snapshot or uncompressed snapshot by function name.

Solution: Provide a function with the same interface that can store compressed, uncompressed, or both types of snapshots. Adds a new environment variable snapshot_compression_mode. Defaults to compressed

[madninja]

I'd rename it to save_bin_snapshots (note the plural) and use that as the single entry point for multi binary snapshot saves? Keeps the name more consistent imo