notifications: show notifications for all active dates

[Maltimore]

This seems like an obvious/easy fix, but maybe (probably) there was a reason it wasn't done like this to begin with?
It works for me so far.
Closes #374

[Maltimore]

I just noticed that this still doesn't work for repeater dates. (But I guess this PR is already an improvement over the status quo).

[jgollenz]

I think this should be a configurable option. This way it doesn't break current behavior. What do you think?

[dtvillafana]

I have made the same change in my fork, and the reasoning in the linked issue is sound and I agree with it, but from a software product standpoint it would make sense to make it a configurable option for backwards compatibility and extensibility.

[Maltimore]

Hey, sorry for not getting back to you @jgollenz, and thanks for your interest @dtvillafana. I'm still using this patch as well.
Making it configurable is of course always an option but to be honest I see absolutely no reason not to include active dates in the agenda, I mean otherwise what's the difference to passive dates?

[Maltimore]

Sorry, forget what I said. This is not about the agenda but about notifications. Yes I suppose one could have a config option whether to show notifications for active timestamps. I still wonder what the reasoning is to not show notifications for timestamped events by default, but to show them for SCHEDULED and DEADLINE.

[jgollenz]

I took a look at the docs and actually the behavior you expect should already be happening, so strictly speaking this is a bug fix 😉 It says agenda tasks notifications there, so you are absolutely right. We also already have options for this, albeit the other way round:

deadline_reminder = true,
scheduled_reminder = true,

I tested your change and it looks good to me. When you mark the PR as ready I can merge it 👍

[jgollenz]

it would make sense to make it a configurable option for backwards compatibility and extensibility

@dtvillafana in this case behavior was actually not in line with what the docs say, so I don't consider it necessary to add an option. If need for it exists, we can think of introducing it but for now this is a bug-fix.

[Maltimore]

Ok, ready for review!

[jgollenz]

Did some more checks and it seems that

deadline_reminder = false,
scheduled_reminder = false,

have no effect any more. I get notifications for both DEADLINE and SCHEDULED tasks even when they should be turned off. Can you confirm this?

[Maltimore]

Ah yes, you're right!
Sorry, I was too eager to just fix my own use-case and didn't think about these settings. I'll have to make this PR much more through. I'll switch it back to draft.