Implement "admin only" commands

Description

We need a way to limit some commands to be run by only bot admins (people who are responsible for maintaining the server and this codebase).

[x] Read discord IDs of admins that must be set in .env file.
[x] Add a check function that checks if a given member ID is a bot admin.
[x] Make backend_info an admin command.
[ ] unverify (ref: #10)
[x] Make query/role admin-able commands so that admins can run it outside the "academic server" constraint.
[ ] We can later add more admin-convenience functions usable from discord, stuff like logs/status/ping commands.