Added nbt_storage() scapet function (#655)

* Added storage() scarpet function

Allows you to easly manage vanilla data command storage

* Added docs and uniformed with scoreboard()

storage(key, nbt) will now return the previous value to be consistant with the scoreboard() command.

* Included imports

* Renamed storage function to nbt_storage

* Update docs/scarpet/api/Auxiliary.md

Co-authored-by: gnembon <41132274+gnembon@users.noreply.github.com>

docs/scarpet/resources/editors/idea/2.txt

@@ -67,6 +67,7 @@ map_colour
 material
 modify
 nbt
+nbt_storage
 neighbours
 opacity
 parse_nbt