[loader] Cache CompiledModule separately from Module (#970)

Separates verification, which blesses `CompiledModule`s from loading
which caches `Module`s:

- Renames the existing cache as `loaded_modules`.
- Moves `CompiledModule` out of `Module` and into its own cache
  -- `compiled_modules` -- populated during verification (which
  now no longer populates `loaded_modules`).
- `ModuleCache::insert` now recursively adds `Module`s, `Function`s,
  and `Struct`s (ensuring dependency modules are loaded first),
  assuming the all dependencies have been verified (failing
  otherwise).
- Public APIs into the loader that previously returned `Arc<Module>`
  now also return a `Arc<CompiledModule>`.

This change is motivated by the fact that in the presence of package
upgrades, a single `CompiledModule` can end up being stamped out as
multiple `Module`s

Test Plan:

```
move$ rm -rf ~/.move && cargo nextest
```

Author: amnn

language/move-vm/integration-tests/src/tests/loader_tests.rs

@@ -88,12 +88,12 @@ impl Adapter {
 
         for module in modules {
             let mut binary = vec![];
-            module
-                .serialize(&mut binary)
-                .unwrap_or_else(|_| panic!("failure in module serialization: {:#?}", module));
+            module.serialize(&mut binary).unwrap_or_else(|e| {
+                panic!("failure in module serialization: {e:?}\n{:#?}", module)
+            });
             session
                 .publish_module(binary, WORKING_ACCOUNT, &mut UnmeteredGasMeter)
-                .unwrap_or_else(|_| panic!("failure publishing module: {:#?}", module));
+                .unwrap_or_else(|e| panic!("failure publishing module: {e:?}\n{:#?}", module));
         }
         let (changeset, _) = session.finish().expect("failure getting write set");
         self.store
@@ -106,9 +106,9 @@ impl Adapter {
 
         for module in modules {
             let mut binary = vec![];
-            module
-                .serialize(&mut binary)
-                .unwrap_or_else(|_| panic!("failure in module serialization: {:#?}", module));
+            module.serialize(&mut binary).unwrap_or_else(|e| {
+                panic!("failure in module serialization: {e:?}\n{:#?}", module)
+            });
             session
                 .publish_module(binary, WORKING_ACCOUNT, &mut UnmeteredGasMeter)
                 .expect_err("publishing must fail");