Make CarpetContext's new constructor take a CarpetScriptHost

Many users assume it is, and all callers pass it anyway. At some point `host` access could be made a function so CC could override it and return `CarpetScriptHost` without requiring casts

src/main/java/carpet/script/CarpetContext.java

@@ -9,7 +9,7 @@ public class CarpetContext extends Context
     public CommandSourceStack s;
     public final BlockPos origin;
 
-    public CarpetContext(ScriptHost host, CommandSourceStack source) {
+    public CarpetContext(CarpetScriptHost host, CommandSourceStack source) {
         this(host, source, BlockPos.ZERO);
     }