[DNM][DNM][WIP] Projectile backend code port and update

Ports#54924,  #65061, #59804 from /tg.
adds auxiliary code from /tg to make code work.

code/__DEFINES/projectiles.dm

@@ -1,3 +1,14 @@
+
+// check_pierce() return values
+/// Default behavior: hit and delete self
+#define PROJECTILE_PIERCE_NONE 0
+/// Hit the thing but go through without deleting. Causes on_hit to be called with pierced = TRUE
+#define PROJECTILE_PIERCE_HIT 1
+/// Entirely phase through the thing without ever hitting.
+#define PROJECTILE_PIERCE_PHASE 2
+// Delete self without hitting
+#define PROJECTILE_DELETE_WITHOUT_HITTING 3
+
 /// This atom should be ricocheted off of from its inherent properties using standard % chance handling.
 #define PROJECTILE_RICOCHET_YES 1
 /// This atom should not be ricocheted off of from its inherent properties.