One-off custom notification support

[BeardedWatermelon]

Description

When it comes to notifications, we are currently limited to the pre-existing default notifications, we cannot send any custom notifications to our users.

Desired Behavior

Add the ability to send your own custom one-off notifications to specific users, same way that Ombi allows. There's a similar issue #405 but it's more about customising the existing default notifications.
This request is about just selecting some users, typing some text, and sending it as a notification.

Additional Context

No response

Code of Conduct

• I agree to follow Overseerr's Code of Conduct

[johnoldiges]

Would also be nice to have an option with the notifications for mass email to the emails associated with the users plex account if signed in via plex.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[BeardedWatermelon]

bump because I believe this is a useful feature.

[RebeliusGaming]

I agree, would love this feature too

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[RebeliusGaming]

Can we keep this open?

[BLTplayz]

Bump, would love to see this come to fruition!

[tarunkumar519]

Bump, this will be such a useful feature

[MrTurtles]

Why is this not a thing yet?

[iris1801]

Bump, really need this

[redux777]

Bump. Overseerr is my pane of glass for my users. It would be very useful to communicate updates or send maintenance notifications as Overseerr already aggregates their email addresses.

[RebeliusGaming]

As this looks like it won't be implemented, I'm unsubscribing.
Thanks for your efforts and hope you can add this functionality in the future