Update plugin test framework to junit5

Updates the testing infrastructure to use the latest relesae of junit and
leverages the new extension mechanism to create an easy to use testing
framework.  Also adds additional test coverage for several plugins.

game/plugin/skills/prayer/src/BoneBuryAction.kt

@@ -25,7 +25,7 @@ class BuryBoneAction(
     }
 
     companion object {
-        private val BURY_BONE_ANIMATION = Animation(827)
+        public val BURY_BONE_ANIMATION = Animation(827)
         internal const val BURY_OPTION = 1
     }
 

game/plugin/skills/prayer/src/prayer.plugin.kts

@@ -34,4 +34,4 @@ on { ItemOptionMessage::class }
 
         player.startAction(BuryBoneAction(player, slot, bone))
         terminate()
-    }
+    }