chore: Clean up unused files, imports, and work on getting end-to-end tests and unit tests running (#2272)

docs/v2/services/ui/ui-dialog-service.md

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+# UI Dialog Service
+
+Dialogs have similar characteristics to that of Modals, but often with a
+streamlined focus. They can be helpful when:
+
+- We need to grab the user's attention
+- We need user input
+- We need to show additional information
+
+If you're curious about the DOs and DON'Ts of dialogs and modals, check out this
+article: ["Best Practices for Modals / Overlays / Dialog Windows"][ux-article]
+
+<div style="text-align: center;">
+  <a href="/assets/img/dialog-example.gif">
+    <img src="/assets/img/dialog-example.gif" alt="UI Dialog Service Example" style="margin: 0 auto; max-width: 500px;" />
+  </a>
+  <div><i>GIF showing successful call of UIDialogService from an extension.</i></div>
+</div>
+
+## Interface
+
+For a more detailed look on the options and return values each of these methods
+is expected to support, [check out it's interface in `@ohif/core`][interface]
+
+| API Member     | Description                                            |
+| -------------- | ------------------------------------------------------ |
+| `create()`     | Creates a new Dialog that is displayed until dismissed |
+| `dismiss()`    | Dismisses the specified dialog                         |
+| `dismissAll()` | Dismisses all dialogs                                  |
+
+## Implementations
+
+| Implementation                       | Consumer                   |
+| ------------------------------------ | -------------------------- |
+| [Dialog Provider][dialog-provider]\* | Baked into Dialog Provider |
+
+`*` - Denotes maintained by OHIF
+
+> 3rd Party implementers may be added to this table via pull requests.
+
+<!--
+  LINKS
+-->
+
+<!-- prettier-ignore-start -->
+[interface]: https://github.com/OHIF/Viewers/blob/master/platform/core/src/services/UIDialogService/index.js
+[dialog-provider]: https://github.com/OHIF/Viewers/blob/master/platform/ui/src/contextProviders/DialogProvider.js
+[ux-article]: https://uxplanet.org/best-practices-for-modals-overlays-dialog-windows-c00c66cddd8c
+<!-- prettier-ignore-end -->