'/loot' position is always floored

The bug

When setting the position in the /loot command, the resulting location is always in the lowermost corner of the block; i.e. the coordinates get floored down. This has some useful applications, but it ruins the intended use case of /loot (spawning loot at a specific location).

Steps to reproduce:

• Summon loot through /loot, and set the coordinates to the center of a block. The "entities/panda_sneeze" loot table always drops one slime ball. Here's an example that would spawn loot at the center of (0, -60, 0).

  /loot spawn 0.5 -60.0 0.5 loot "entities/panda_sneeze"
  

→ The slime ball spawns in the lowest corner, rather than in the center.