Implement Accessibility Features

[a6wu]

Time Tracking: https://its-pro.ucsd.edu/browse/MA-212

Implement accessibility features documented in Campus Mobile (view).
TODO:

• Make the logout button recognizable by voiceover
• Make the slider buttons recognizable by voiceover

Might possibly need another issue to work on webview accessibility as they're much more complicated than the other tasks

[morebytes]

Accessibility bug due to Web View limitations. Blocker until fixed. Issue linked.