feat: group notifications by repository or date

[setchy]

closes #836.

for now I've added this as another Notification Setting flag.

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I've been thinking that in the near future it may make sense to pull out all of our filter-based settings into either their:

• own settings section ie: Notification Filters
• dedicated Filters page with access from the sidebar

Types of filter-based settings would include

• group by repository or date
• show/hide Bot notifications
• show/hide by notification reason Allow for simple reason filtering #264
• etc

[afonsojramos]

I know it is easier to just add a checkbox, but I don't think with a checkbox it is clear what the alternative behaviour is 🤔 Can we use a select instead?

[setchy]

I know it is easier to just add a checkbox, but I don't think with a checkbox it is clear what the alternative behaviour is 🤔 Can we use a select instead?

great feedback. updated to be a radio group

[afonsojramos]

Looking good!! I think this will be one that a good subset of users will enjoy!