Get a Notification if the bot permissions are insufficient while there are active giveaways

If an admin changes bot permissions in a way that will prevent the bot from ending a giveaway it would be helpful to get some kind of warning or notification or have a command for status to check permissions after roles changes are made.

Start by reviewing how active giveaways and bot permissions are represented, then determine where permission changes can be detected. Done should provide an actionable warning or a status command when the bot can no longer end an active giveaway.

Written by the indexing model from the issue text.