* Add Theme v2 name to non-external modules when starting webpack

[KristianDD]

Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI:
• Cross-platform modules:
• Android Runtime:
• iOS Runtime:
• Plugin(s):

Describe the bug

The theme v2 is considered an external package and is not included in the vendor.js file.

To Reproduce

1. Install Preview app which includes @nativescript/theme
2. Create an application from templates master branch
3. tns preview android/ios
4. scan with a device

Expected behavior
Theme v2 to be included in the vendor.js file.

Sample project

Additional context