Provide built-in implementations of module linker, initializeImportMeta, importModuleDynamically

**Is your feature request related to a problem? Please describe.** When using vm.SourceTextModule we have to implement a linker, initializeImportMeta, and importModuleDynamically, even if we just want the default behavior of built-in module support. There are many subtle ways to get that wrong. **Describe the solution you'd like** Default implementations that do basically what built-in module support does: - A linker function that: - Reads files from disk, within a specified root. - Uses Node module resolution as implemented for modules - Uses a specified module cache - `initializeImportMeta` that sets `url` property - By configuration, allows access to built-in modules. **Describe alternatives you've considered** Userland libraries can take the first cuts at easy-to-use vm.Modules, but I think something for common use cases should likely be included.