As an administrator I want to be able to change volunteer's permission

Administrators should be able to changes volunteer's permissions. Admins should have access to an admin page where they can view all accounts in a table format. Here they can search for a specific account and click on a more info link (available for each row) which redirect to a new view in a new tab, which shows a user's information. They can then view and edit the details on the new tab including their permissions. This functionality should only be available to superusers.

**Tasks**

Frontend
- [ ] Admin route
- create a route that only coordinators and above can access (e.g. /admin)
- restrict access using the user's list of permissions (see backend tasks)
- this base admin page should contain links to other admin pages
- [ ] Roles & Permission admin page
- create an admin page and add a link to the base admin page created in the task above
- this page lists all users on the system (paginated) using a backend API endpoint
- clicking on a user opens up a modal that displays their details as well as the roles and permissions that they have
- roles and permissions fields are represented as pills that has an x button, when users click this button it removes the role or permission from the user
- roles field and permissions field should also have a + button that allows users to add a new role/permission to the user. the list of roles and permissions should be fetched from a backend API endpoint

Backend
- [ ] List user's permission endpoint
- GET request, given a user's email/id, return all of their unique permissions (combine both direct permissions and permissions granted through
- [ ] List all users endpoint
- GET request, return a list of all users including their details as well as all of their roles and permissions
- this endpoint should be paginated. ie given a page number, return x number of users.
- e.g. page size is 20. page no 1 = first 20 users, page no 2 = user #21 > user #41, etc
- designate permission to this endpoint (e.g. `read:users`) and restrict it to administrators
- [ ] Add permission endpoint
- POST request, given a user id and a permission name, add that permission to the user
- designate permission to this endpoint and restrict it to superusers (execs)
- [ ] Add role endpoint
- POST request, given a user id and a role name, add that role to the user
- designate permission to this endpoint and restrict it to superusers (execs)
- [ ] Remove permission endpoint
- DELETE request, given a user id and a permission name, remove that permission from the user
- designate permission to this endpoint and restrict it to superusers (execs)
- [ ] Remove role endpoint
- DELETE request, given a user id and a role name, remove that role from the user
- designate permission to this endpoint and restrict it to superusers (execs)