Feat/hng 55 super admin add user modal components

[emaicorp]

Description

closes #55

**Closes #55 **

Changes proposed

What were you told to do?

Super Admin Add user modal components

What did you do?

implemented the Add User Modal components ensuring consistency with ShadCN UI components.
i edited the root.tsx file to add modalProvider context to allow access to the add user button i created on the _index.tsx file in app(folder).
created formComponent folder that holds the form file and the function file it uses to full implemented , made sure to use seperation of concern to break my code into segments for easy read and fix in the future.
i only installed the dependencies in the package.json file

Check List (Check all the applicable boxes)

🚨Please review the contribution guideline for this repository.

[x]-Component Should be pixel perfect as implemented using ShadCN UI.
[x]- Implement interactions with the component

• [ x] My code follows the code style of this project.
• [ x] This PR does not contain plagiarized content.
• [ x] The title and description of the PR is clear and explains the approach.
• [x ] I am making a pull request against the dev branch (left side).
• [x ] My commit messages styles matches our requested structure.
• [x ] My code additions will fail neither code linting checks nor unit test.
• [ x] I am only making changes to files I was requested to.

Screenshots/Videos

Uploading boiler_plate.mp4…