Enhancements to the Admin dashboard page

[utsab]

This issue is related to Issue #467 and PR #468. The referenced PR did successfully refactor the table on the admin page to use react-table. However, the PR introduced a few discrepancies compared to the original design of the admin table.

Original admin table:

New admin table (after PR 468) :

The goal of this issue is to fix the following discrepancies:

1. The new admin table is missing a footer where the user can change the number of entries per page
2. The "UserEmail" column should be titled "Email"
3. The styling has changed. If possible, use the previous styling where there was no border surrounding the table. There also should be a visible line separating each row.

Steps to recreate the issue:

1. Make sure you can successfully log in via Github (use the Github sign-in option, not Auth0)
2. Run "npx prisma studio" in the terminal, navigate to the "Users" table, change the role of your user to "ADMIN"
3. Make sure you click "Save changes" in prisma studio
4. Sign out of the Classroom app and then sign back in
5. Navigate to the /admin page (type this into the browser)

[Abiral-2724]

hello @utsab
Can you please assign this to me