[terra-application-v2] Update ApplicationBase to align with new architecture

[tbiethman]

Story

Description

As a consumer, I want the ApplicationBase component to be able to work in conjunction with the ApplicationContainer...

Motivation

So that I can utilize i18n/theming in my applications without defects.

Definition of Done

We'll know we're done when ApplicationBase has been updated, tests have been updated, and examples are able to use ApplicationBase and ApplicationContainer without issue.

Details

There are a number of things that have fallen out of date with the v1 branch, I plan on bringing those changes/fixes in with this story. The test implementations may take a hit; I might have to remove tests for components that are to be removed at a later date, or just remove them outright.

Might be able to sneak #165 in there too.

Estimated story points: 3