[Enhancement] [remindme] Limit the maximum time for a reminder

[wasdennnoch]

Currently there is no upper limit on how long in the future a reminder can be, which means that it's possible to create reminders that run in a few centuries or even in Infinity years (thanks JS). While a few of those reminders probably won't be an issue in the long term people could abuse this to add masses of reminders that will practically never fire and just take up DB space and event loop queue items.

I think it would be reasonable to cap the maximum time for a reminder at something like 10 years. I don't think many people set reminders beyond one year, and anything above 100 years is either useless or a user error.