Add iOS 16 support for Live activity iOS notifications

[GonzaloAvilez]

trafficstars

support to live activity payload

adding support to valid keys defined for Live Activity dismissal-date stale-date timestamp even content-state

Apple Documentation reference for aps payload to support live-activity .

support header for liveactivity

Apple Documentation reference for Header aps-push-type.

• Updates readme with additions in payload
• test code and manual tests via command line

[happenslol]

Heya, I'd like to use this. Is there anything keeping this from being merged that I could help with?

[sideshow]

Thanks for this. I ended up merging the similar PR https://github.com/sideshow/apns2/pull/219 which had the same fields.