Ability to filter out `printer-added` notifications in c-s-d/print-notifications

[xax]

 * csd version 4.6.4+ulyana
 * Mint 20
 * 64 bit

Issue Starting a session in a larger LAN environment, c-s-d plugin print-notifications produces a flood of notifications in response to CUPS' printer-added events.

Steps to reproduce Have c-s-d/p-n running and ad your system to a network with plenty of discoverable printers.

Desired behavior Be able to filter event types (e.g. printer-added, printer-deleted, printer-state-changed) in print-notifications.

Other information

• Disabling of the entire plugin dies not yield the desired result, as other printer related notifications, i.e. CUPS events, should well be shown.
• The View » discovered printers setting from system-config-printer does not seem to be related (nor effective).
• Disclaimer: I don't know anything about libnotify and whether it possibly provides mechanisms to filter notifications.