rebuild: include prefix when filtering with --only

The logic currently ignores a module prefix when filtering packages
passed via `--only=`. This is quite confusing: to only rebuild
something like `@theia/node-pty` we must pass `--only=node-pty`.

This commit adds a lookup using the prefixed name.

src/rebuild.ts

@@ -324,7 +324,7 @@ export class Rebuilder {
       }
       this.realModulePaths.add(realPath);
 
-      if (this.prodDeps[`${prefix}${modulePath}`] && (!this.onlyModules || this.onlyModules.includes(modulePath))) {
+      if (this.prodDeps[`${prefix}${modulePath}`] && (!this.onlyModules || this.onlyModules.includes(modulePath) || this.onlyModules.includes(`${prefix}${modulePath}`))) {
         this.rebuilds.push(() => this.rebuildModuleAt(realPath));
       }