To view a full screen avatar for user profiles we are going to want to reuse parts of the `MultimediaModal` component.
However, right now there are parts of `MultimediaModal` that are specific to viewing a multimedia message. We need to factor those parts out, so I created `FullScreenViewModal` which will be a generic component that can be used in both cases for image multimedia messages and user avatars.
Outlined below are the steps I will take in this stack (each point here will be it's own diff):
1. Introduce `FullScreenViewModal` file and move everything from the `ImageModal` file into here, and change what is absolutely necessary (the imports)
2. Lift the rendering of `mediaModalItem` out of `FullScreenViewModal`
3. Finish renaming + updating remaining variables/callbacks to make `FullScreenViewModal` completly generic
4. Introduce `UserProfileAvatarModal`