Adds obstacle blocks for parkour

This change reverts the advanced hit-box detection for kill plane blocks, giving them a full block's hit-box again.
Instead, obstacle blocks have been added, which have an accurate hit-box, and can trigger a hit from any direction.
The horizontal kill plane hit box option has been removed as it's no longer useful.

src/main/java/net/knarcraft/minigames/util/TabCompleteHelper.java

@@ -137,6 +137,7 @@ public final class TabCompleteHelper {
         List<String> suggestions = new ArrayList<>();
         suggestions.add("LAVA,MAGMA_BLOCK");
         suggestions.add("WATER,MAGMA_BLOCK,LAVA,+BUTTONS,+CORALS");
+        suggestions.add("CHAIN,END_ROD,LIGHTNING_ROD");
         return suggestions;
     }