Add method to get ungenerated chunk from long key (#9254)

Also added a missing deprecation for a location block key method

patches/api/Allow-Blocks-to-be-accessed-via-a-long-key.patch

@@ -83,6 +83,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +     * @see Block#getBlockKey(int, int, int)
 +     */
 +    @NotNull
++    @Deprecated
 +    public default Location getLocationAtKey(long key) {
 +        int x = Block.getBlockKeyX(key);
 +        int y = Block.getBlockKeyY(key);