Tags in Pose of armor_stand are removed when containing default values

Maybe cause for:

• MC-80974

The bug

When a tag in the Pose tag of an armor stand contains the default values, it gets removed. This might be useful for saving the NBT data, but this way it is impossible to use NBT comparison to test if one of the tags in Pose has the default values.

How to reproduce

1. Place an armor stand
2. Run this command:

   /data get entity @e[type=armor_stand,limit=1] Pose
   
   Result:
   Pose:{
   	Head:[
   		0:2.8267171f,
   		1:-5.086746f,
   		2:0.0f
   	],
   	Body:[
   		0:0.0f,
   		1:1.7570348f,
   		2:0.0f
   	]
   }
   

3. Run this command:

   /data merge entity @e[type=armor_stand,limit=1] {Pose:{Body:[0f,0f,0f]}}
   
   Result:
   Pose:{
   	Head:[
   		0:0.702278f,
   		1:1.4992895f,
   		2:0.0f
   	]
   }
   

Default values (1.9)

• Head: 0.0f, 0.0f, 0.0f
• Body: 0.0f, 0.0f, 0.0f
• LeftArm: -10.0f, 0.0f, -10.0f
• RightArm: -15.0f, 0.0f, 10.0f
• LeftLeg: -1.0f, 0.0f, -1.0f
• RightLeg: 1.0f, 0.0f, 1.0f