Alphabetize state selection in RegisterForm.tsx

[ameliav]

🗣 Description

Front-end:
The registration form contains a field for selecting US States and Territories. This dropdown is not alphabetized and should do so. This code will be consolidated in a "constants" file for both the organization form and registration form to use. Issue #19

💭 Motivation and context

To improve user experience, we need to sort the states alphabetically.

🧪 Testing

• The US States and Territories dropdown should display options in alphabetical order.
• The sorting should be case-insensitive (e.g., “New York” should come after “North Carolina”).
• The change should be reflected in both the organization form and the registration form.
• Create a centralized function or module that handles state-related logic.
• This function/module should populate the state, stateName, and regionId fields consistently for both User and Organization entities.
• Ensure that the consolidated logic is efficient and maintainable.

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All future TODOs are captured in issues, which are referenced
  in code comments.
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated
  to reflect the changes in this PR.
• Tests have been added and/or modified to cover the changes in this PR.
• All new and existing tests pass.

✅ Pre-merge checklist

• Revert dependencies to default branches.
• Finalize version.

✅ Post-merge checklist

• Create a release.

[Matthew-Grayson]

Perfect!