Notification grouping/summary instead of log notification spam

[frebib]

Is your feature request related to a problem? Please describe.
We use the Slack notifications, and pipe them through a service which forwards them to a Telegram chat, and this has worked fine for years with several Watchtower builds/variations.
The issue is that Watchtower sends 4-6 notifications per container that it updates, which seems excessive

Describe the solution you'd like
Have a configurable to send one summary notification after the job has been done, with detail of which failed, succeeded and updated. Notifications are not logging, so having them decoupled would be good. Also an option to send error logging as notifications additionally would be good.

Describe alternatives you've considered
N/A

Additional context

[github-actions]

Hi there! 👋🏼 As you're new to this repo, we'd like to suggest that you read our code of conduct as well as our contribution guidelines. Thanks a bunch for opening your first issue! 🙏

[simskij]

Hi, and welcome to the community! 🎉

I'm going to close this issue as your feature suggestion is tracked in #255 already.

[ghost]

To avoid important communication to get lost in a closed issues no one monitors, I'll go ahead and lock this issue. If you want to continue the discussion, please open a new issue. Thank you! 🙏🏼