Allow script arrays to hold any value type, add script engine tests, archive old rpg code

Remove the per-array type category so arrays can mix types like structs.
Add 13 passing and 125 expected-failure duskscript test fixtures with a
table-driven runner. Also includes the in-progress entity/physics and
archive moves from the working tree.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

test/duskscript/assets/pass_async.ds

@@ -0,0 +1,26 @@
+async function giveFive() {
+  return 5;
+}
+async function addAsync(a, b) {
+  return a + b;
+}
+async function chain() {
+  var first = await giveFive();
+  var second = await addAsync(first, 10);
+  return second;
+}
+var value = await giveFive();
+assert(value == 5);
+assert(await addAsync(2, 3) == 5);
+assert(await chain() == 15);
+
+var promiseValue = giveFive();
+assert(!isnull(promiseValue));
+assert(await promiseValue == 5);
+
+// Looping with awaits
+var total = 0;
+for(var i = 0; i < 5; i++) {
+  total += await addAsync(i, 1);
+}
+assert(total == 15);