Add irc/znc-push: Push notification service module for ZNC

ZNC Push is a module for ZNC that will send notifications to multiple push
notification services, or SMS for any private message or channel highlight that
matches a configurable set of conditions. ZNC Push current supports the
following services:

Boxcar
Boxcar 2
Discord
Faast
Nexmo
Notify My Android (NMA)
Prowl
Pushalot
PushBullet
Pushjet
Pushover
Pushsafer
Slack
Supertoasty
Telegram
Custom URL GET requests

WWW: https://github.com/jreese/znc-push

PR: 232409
Submitted by: David O'Rourke <dor.bsd@xm0.uk>