Conditional rendering for approve and reject buttons for admin

[MindChirp]

The reservation page must have at least two buttons which should only be visible to the admins;

• Approve button
• Reject button

This means that we need to first be able to fetch and store privilege data about the user, which is currently being implemented in another branch - feat/fetch-user-data.

In other words, this issue is currently being blocked by the aforementioned branch.