Users should be able to configure their notification levels

[ItsMeBrianD]

Currently, users are at least:

• DM'd by the bot for scrim status changes
• Pinged by the bot when report cards post

We should make this behavior configurable to let players disable notifications that they don't want.

For disabling scrim status changes, we should group it into "time sensitive" and "other", so they can disable some notifications, while still getting notifications for things like scrim pops.

TBD if this should go onto the User table, or a UserSettings table, but I would lean towards UserSettings

[ItsMeBrianD]

Regarding the report cards post; the user should still have a silent mention if the setting is disabled