DM reminders to "slow" quantifiers automatically

[mattyg]

Currently there is a lot of "cat-herding" required by administrators to ensure all quantifiers complete their work on time.

To reduce this workload, we could instead automatically send DMs to remind slow quantifiers that they need to complete their quantifications.

It could send a message to all quantifiers with outstanding incomplete quantifications X days before the period ends.

This could also defined via a period setting.

See #173

Original Message:

Kristofers idea - when someone needs to be removed for not showing or not completing in a timely manner we remove them from the active quant and a message is sent to all other quantifiers in the pool that there is a spot available - the first to respond gets the open spot.

Originally posted by @divine-comedian in #173 (comment)

[divine-comedian]

it's a cool issue but if we should think of any ways to oversee the system and make sure it's working.

for example after introducing the bot command to notify all active quantifiers we realized some people wouldn't received messages from the bot due to their personal discord settings, meaning in order to be sure I had to DM them all one by one, same as before, due to this issue #317