Add permission checks to p.prefix command

src/framework/commands/mod.rs

@@ -33,6 +33,9 @@ pub enum CommandError {
 
     #[error(transparent)]
     DiscordDeserializationFailed(#[from] DeserializeBodyError),
+
+    #[error("The cache's state was inconsistent.")]
+    CacheStateInconsistent,
 }
 
 #[async_trait]