Custom Element not working with symlinked aurelia-plugin library

**I'm submitting a bug report**

* **Library Version:**
4.0.0

**Please tell us about your environment:**
* **Operating System:**
Windows 10

* **Node Version:**
10.17.0

* **NPM Version:**
6.11.3

* **Webpack Version**
webpack 4.43.0

* **Browser:**
all

* **Language:**
TypeScript 3.8.3

**Current behavior:**

I have a monorepo setup as follows:
|- plugin-test (Aurelia Plugin project, built with `au new --plugin`)
|- app-test (Aurelia app project, build with `au new`)

I used npm (with a symlinked file version) to install the plugin-test plugin into the app-test app. The sample attributes, binding-behaviors, and value-converters all work fine in the app-test app. However, the `` element does not render.

**Expected/desired behavior:**
I expected the `` element to work. I also tried using the `@inlineView`, `@useView` and `@useView(PLATFORM.moduleName("..."))` decorators (and then rebuilding the plugin library with `au build-plugin`), but that did not seem to help.

I created a reproduction here: https://github.com/alexisszabo/aurelia-plugin-element-issue

This issue seems related to https://github.com/aurelia/webpack-plugin/issues/164, but I have had no success with the suggestions there. It looks like I should ideally be using `@fromView` in my plugin library for custom elements, but that did not seem to work for me.

Start with the linked reproduction repository and inspect how the symlinked plugin is built and installed in app-test, focusing on the custom element that fails while the other plugin resources work. Verify the behavior with the reported Aurelia and webpack versions; done means that renders from the symlinked plugin.

Written by the indexing model from the issue text.