Have chests and chest contents stored fully in region files

At present, in Java Edition, there is an issue with moving regions from one world to another. Specifically, both the chests and chest contents disappear when they move to a new world. In order to make the chests appear in 1.16.3 and 1.16.5 you need to approach the chest in spectator mode while in the latest snapshot - 21w08b - there is no way to recover it. Regardless though, the chests are empty.

This is a problem with world downloads in particular (especially when trying to share custom made dungeon maps), as well as recovery options regarding otherwise corrupt worlds. This seems to be due to the reliance on level.dat and level.dat_old containing the information. This both causes chests to be empty when backing up and enables chest duplication exploits to occur again and again. 

To fix this behavior, I would like for all chests and chest contents to be stored fully in region files just like any other block. This will allow proper backup of region files and keep chest duplication exploits from recurring.

This suggestion applies to all types of storage that can be placed in the world aside from Ender Chests (which are part of a player's inventory)..