Todo: Handle potential NREs

[FloatingMilkshake]

There are many potential NREs that I brush off because they aren't important, but they might cause issues later. They should be handled instead of being ignored. Be on the lookout for the null-forgiving operator (!) too; oftentimes I will use it and then not check for null properly and an NRE will be thrown there.

(Also: yes DiscordClient.CurrentApplication.Owners can be null, happens when the bot is owned by a team)

[FloatingMilkshake]

This is pretty much blocked on DSharpPlus, waiting for proper nullable annotations