[feature request] Messages sent while the contact is offline arrive with the timestamp of arrival

[yurivict]

When both users aren't simultaneously online and there is a significant difference between sent and received times both times should be displayed on both ends. Currently toxcore doesn't provide such capability.

My original report to qTox: qTox/qTox#3306

[GrayHatter]

Toxcore would need to handle and store offline messages, currently it does neither.

[yurivict]

Clients should store and supply the creation/sent time to toxcore then, and toxcore should provide received time.

[isotoxin]

Isotoxin already do it. But only with Isotoxin-Isotoxin connections.
This can be done compatible in context of #1519

[yurivict]

When the message is stored or transmitted it should always be accompanied by the metadata, similar to an http headers. This metadata could contain this "sent" time, also possibly the background color, and all sorts of other fields that the client can send to make messages more flexible and feature-rich.

[SkyzohKey]

If you're gonna implement more meta datas, please encrypt them.

[aaannndddyyy]

Needed feature.
Current timestamps are useless in that situation.