Add FullScreen React component

[aduth]

Relates to: LG-3094, LG-3023
Currently configured to merge to (blocked by) #3931 in order to leverage assets behavior

Why: As a user trying to proof, I want the capture mode to be more intuitive in landscape and portrait orientation, so that I can easily capture images of my IDs and selfie.

The changes in this pull request introduce a new React component <FullScreen />, implementing the behavior of a dismissible full-screen modal dialog. This is currently integrated in the work-in-progress single-page document authorization upload flow, shown in response to clicking the "Take photo" button in the verification step.

Screenshot:

Before Activating	After Activating

Notes:

• The desktop experience doesn't currently support camera capture, so the content is expected to be empty. A prompt will appear to upload a photo.
• Changes were needed to the testing setup, since I encountered that the existing focus-trap dependency has side effects in its imports which depend on DOM globals. These changes are included here, though could make sense to break off into a separate pull request. Overall it should simplify authoring tests in many cases.

[zachmargolis]

LGTM

[aduth]

Summarizing the discussion at #3938 (comment) :

• focus-trap is quite good at what it seeks to achieve, and despite the specific integration here in React being clunky, it doesn't appear the alternatives explored provide much benefit, and often have their own disadvantages.
• There are potential use-cases for a focus trap beyond how we're using it here, and it may make sense to create some abstraction of useFocusTrap or a FocusTrap component.
• However, it's yet to be seen what those specific requirements may be, and since this could be a driver for how the interface ought best to be defined†, I'm inclined to keep this implementation as-is, and wait for those requirements to develop.

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† For example, should it behave like focus-trap-react and accept an object of all focusTrapOptions? Will we need all of those? Or does an onRequestClose suffice? How best should we handle changed values for each of these options?