Modular Loading Component (CRASM-2949)

[hawkishpolicy]

🗣 Description

• Added loadingText state to AuthContext.
• Updated return of AuthContextProvider to use new MUI CircularProgress, Typography, and Alert components.
• Developers can now set loadingText to provide context during loading states which are triggered by API requests.

💭 Motivation and context

• Provide a modular and programmatically determined Loading notification high in the react tree, in this case at the Auth Context level, with state that can be imported into any file. Thus enabling an easy and uniform manner to set state and render Loading notifications and placeholder divs throughout the app.
• Closes CRASM-2949

🧪 Testing

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All new and existing tests pass.
• Bump major, minor, patch, pre-release, and/or build versions as appropriate via the bump_version script if this repository is versioned and the changes in this PR warrant a version bump.
• Create a pre-release (necessary if and only if the pre-release version was bumped).

✅ Pre-merge checklist

• Revert dependencies to default branches.
• Finalize version.

✅ Post-merge checklist

• Create a release (necessary if and only if the version was bumped).

[schmelz21]

Determined 11/5 - Hold in draft as may be needed at a later date.