Store game state as SnapShot

As a user I want to be able to store the current game state.

Create mechanic to determine a filename for the new snapshot. The file should be in the format savegame-00000.zip, counting up
Create a zip file that stores the new snapshot (json), which is in the format savesgames/savegame-00000.json within the file. The number should mirror the archive's filename number
Set the basic header information in the file
Add support for a timestamp in the save snapshots
Apply the data structures
- basic/world data
- wall data
- portal data
- object data

Edited Aug 18, 2021 by simon