replace DeleteMessageDays with DeleteMessageSeconds and make AddBan take a Duration

[mlnrDev]

discord/discord-api-docs#5219

[mlnrDev]

alternatively, we could deprecate DeleteMessageDays and change this method to take discord.AddBan instead of a value and allow the user to choose which field they want to use before delete_message_days gets removed in the next API version. it'd still be breaking, but it'd at least allow the user to take advantage of something which still works while adding support for the new field.

[topi314]

hm this one is quite annoying as it doesn't break the method signature. What if we instead make the method take time.Duration?
sadly this will still not break the signature and could lead to confusion. On the flip side I don't think a lot of people use(if any) so if we break it now it should be fine