fix(ngcc): handle CommonJS re-exports by reference (#34254)

In TS we can re-export imports using statements of the form:

```
export * from 'some-import';
```

This can be downleveled in CommonJS to either:

```
__export(require('some-import'));
```

or

```
var someImport = require('some-import');
__export(someImport);
```

Previously we only supported the first downleveled version.
This commit adds support for the second version.

PR Close #34254

packages/compiler-cli/ngcc/test/host/commonjs_host_spec.ts

@@ -557,7 +557,8 @@ exports.xtra2 = xtra2;
     function __export(m) {
       for (var p in m) if (!exports.hasOwnProperty(p)) exports[p] = m[p];
     }
-    __export(require("./b_module"));
+    var b_module = require("./b_module");
+    __export(b_module);
     __export(require("./xtra_module"));
     `
         },