Add push/desktop notification settings (or a link to it)

### How to use GitHub

* Please use the 👍 [reaction](https://blog.github.com/2016-03-10-add-reactions-to-pull-requests-issues-and-comments/) to show that you want to have the same feature implemented.
* Please don't comment if you have no relevant information to add. It's just extra noise for everyone subscribed to this issue.
* Subscribe to receive notifications on status change and new comments.

### Feature description
Currently, it's possible to enable certain push notifications in the web client settings, which will enable desktop notifications through the client. However, if a user only uses the desktop client, there is no way for them to know that such settings exist as they are not mentioned anywhere within the desktop client. I would therefore suggest that these settings are made available inside the desktop client too or that at least a link to these settings within the web client is included in the settings dialog. This way users can be made aware of these options in a location they would expect.

Start by reviewing the desktop client's settings dialog and the existing web client push-notification settings. Decide whether the desktop client should expose those settings directly or link to them, then verify that users can discover and access the notification controls from the desktop client.

Written by the indexing model from the issue text.