Only effects trapdoors with block state bottom, or "half: bottom"

Tested on multiple types of trapdoors for consistency.

The trapdoors with the bottom block state played the walking sound of the block below, while the trapdoors with the top block state played their expected sound effects.

Also affects the particle that appears when running over the trapdoors, showing the particle of the block below them.

Only tested on most recent snapshot, may affect previous versions as well.