Add logging of presence and reactions with timestamps

[cryptCEE]

Log presence events to a file/table

Reaction timestamps: The reactions BLOB format stores sender + emoji but no timestamp field. The WhatsApp protocol does include reaction timestamps, but nchat drops them during serialization. Add presence logging and reaction timestamp storage in a future version.

[d99kris]

I am a little reluctant to it, it seems it would only be useful for tracking other people. Am I missing some legitimate use case for it..?

[d99kris]

I will close this feature request for now as out of scope for this project.