Add a new preference to silence notifications

[garethwhittaker]

What it does

Resolves #5942

Provide users with the option to silence notifications, no longer showing the toasts whilst still being viewable in the status bar counter and accessible via the notifications centre.

How to test

• Ensure notification toasts continue to appear by default (workbench.silentNotifications: false).
• Set preference workbench.silentNotifications: true, then check that toasts no longer appear.

Review checklist

• as an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• as a reviewer, I agree to behave in accordance with the review guidelines

[vince-fugnitto]

Thank you for your contribution @garethwhittaker, I tested the changes and they work well!
I'll give @AlexTugarev a chance to take a look since he was the original author.

[kittaakos]

Do we want to align the preference key with VS Code? They use zenMode.silentNotifications.

[vince-fugnitto]

Do we want to align the preference key with VS Code? They use zenMode.silentNotifications.

I wasn't sure since we do not have the concept of zen mode. In VS Code, notifications can only be silenced in this mode which is not the same behavior we are going for.

[kittaakos]

I wasn't sure since we do not have the concept of zen mode. In VS Code, notifications can only be silenced in this mode which is not the same behavior we are going for.

OK, I am a little bit off from this loop. What if there is a .vscode folder with zenMode. silentNotifications settings, do we ignore it?

[akosyakov]

OK, I am a little bit off from this loop. What if there is a .vscode folder with zenMode. silentNotifications settings, do we ignore it?

@kittaakos zenMode is just an editor without anything else. This PR adds something like do not disturb mode regardless in which mode. I don't think VS Code support it.

[akosyakov]

@vince-fugnitto Don't forget to help merging.

[vince-fugnitto]

@vince-fugnitto Don't forget to help merging.

Sure! I just wanted to give an opportunity for others to take a look as well if they wanted to.

[vince-fugnitto]

@garethwhittaker I wanted to give time for others to check the pull-request but haven't gotten any additional feedback so I think it's good to merge. Can you rebase the pull-request to address the merge conflict?

[vince-fugnitto]

Thank you for your contribution @garethwhittaker!