194 dev camila/implement frontend for bcan poc dropdown

[camila-carrillo]

ℹ️ Issue

Closes #194

📝 Description

Write a short summary of what you added. Why is it important? Any member of C4C should be able to read this and understand your contribution -- not just your team members.

Implemented a searchable dropdown for selecting a BCAN POC when creating/editing a grant. This is important because it ensures a valid BCAN POC is tied to every grant.

Briefly list the changes made to the code:

1. Created a UserDropdown component that displays active users with name and email.
2. Integrated the new component into NewGrantModal (which is also used for editing).
3. Made the email field read-only.
4. Added automatic user fetching when NewGrantModal opens. (shoutout pr 215)
5. Dropdown is scrollable when there are many users and also has search/filter functionality.

✔️ Verification

What steps did you take to verify your changes work? These should be clear enough for someone to be able to clone the branch and follow the steps themselves.

I added one active user to the database to ensure the dropdown was scrollable. I ensured that when I click on the BCAN POC name field the dropdown autopopulates (for both creating and editing). I ensured that the dropdown saves correctly in a creating and editing scenario by using the feature as a user would.

Test Changes

If your new feature required some test to be changed or added to fit the new functionality or changes please document these changes here.

🏕️ (Optional) Future Work / Notes

Fetch users from login perhaps.
When you edit a grant you have to reenter all info, and then instead of editing the existing grant, it makes a new grant with the new info.