Dropdown, TextInput, and Modal Components - Add Missing Props Needed for Faculty Admin Modals

[natalynyu]

This PR adds missing properties needed to create the Faculty Admin modal.

Dropdown: disabled and required properties were added for form validation purposes. TextInput: required property was added for form validation purposes. Modal: aria-labelledBy property was added for accessibility purposes.

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] I have run eslint on the code
• [x] I have added JSDoc for all of my code (where applicable)
• [ ] I have added tests to cover my changes.

Priority:

• [x] Normal
• [ ] High

Related Issues:

Addresses #214

[codecov[bot]]

Codecov Report

Merging #64 into develop will not change coverage. The diff coverage is 100.00%.

@@            Coverage Diff            @@
##           develop       #64   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           32        32           
  Lines          388       397    +9     
  Branches        42        42           
=========================================
+ Hits           388       397    +9     

Impacted Files	Coverage Δ
src/Buttons/BorderlessButton.tsx	100.00% <ø> (ø)
src/Buttons/Button.tsx	100.00% <ø> (ø)
src/Dropdown/Dropdown.tsx	100.00% <100.00%> (ø)
src/Forms/TextInput.tsx	100.00% <100.00%> (ø)
src/Modals/Modal.tsx	100.00% <100.00%> (ø)
src/Tables/TableCell.tsx	100.00% <100.00%> (ø)

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