xCenter and zCenter not set correctly for given filled_map

Issue: When giving a player a filled_map with a set target in the Decorations field of the NBT, the xCenter and zCenter fields of the map_0.dat structure are not set correctly, resulting in a map that doesn't work properly.

Scenario: Give a player an Ocean Explorer Map given the Coordinates of the Monument

Steps to Reproduce:

1. Open the Minecraft 1.14.4 Client

2. Create a New World, with Cheats ON and give it the Seed of Map Test.

3. Login to the newly created world

4. Change to creative mode with the following command:

   /gamemode creative

1. Find the location of the nearest Ocean Monument with the following command:

   /locate Monument

1. The Ocean Monument should be located at [272, ~, -256]

2. Give the player (tester1) an Ocean Monument filled map with the following command:

   /give tester1 minecraft:filled_map{display:{Name:'{"translate":"filled_map.monument"}',MapColor:3830373},Decorations:[\{id:"+",type:9b,x:272.0d,z:-256.0d}]} 1

1. This will give the player an Ocean Explorer Map

2. Save the game and exit out

3. Open up the map_0.dat file under the minecraft folder such as .minecraft/saves/New World/data/map_0.dat using an NBT editor.

4. Look at the entries under the data compound tag xCenter and zCenter.  These values will be -576 and 448 accordingly.
   

   [media]

5. These values don't represent the location set in the Decorations for the Ocean Monument, nor the value of the location of the player when generating the map.

Expectations: When the player uses the /give command to give any player a filled_map and the NBT is supplied for the item that includes Decorations that specify the x and z coordinates, the map should be created with a center based on those x and z coordinates.