Bug: ensure that required fields are properly labeled

[ethangardner]

Describe the bug
Throughout the application, required fields need to be properly marked to indicate that input is mandatory. They are not currently or are done inconsistently. This needs to be done to ensure compliance.

To Reproduce
Look at the source code and rendered output. The required attribute is missing, as well as a visual indicator of required status.

Expected behavior
I expect a visual and screen-reader compatible indication that input is required.

Additional context
There is some guidance on the following resources:

• WAI - https://www.w3.org/WAI/WCAG22/Techniques/aria/ARIA2
• USWDS - https://designsystem.digital.gov/components/form/