prop278: Make the current 'torgzip' module a submodule of a new 'compression' module

• Create a new 'compression' module to handle all compression schemes.
• Refactor the current 'torgzip' module into a module that handles only GZip and deflate, but adheres to the 'compression' module API.
• Create modules for the new compression schemes: LZMA2 and Zstd.