Support for markAsDelivered and auto message delivery and reading.

[HossamMohsen7]

Facebook in the browser marks new messages as delivered, So I added that here with the abillity to make it automatic (On by default). Also made an option to make markAsRead automatic but it's not on by default.

I don't know for sure if marking messages as delivered helps with the issue of accounts getting blocked, but it's better to do it anyway.

I fixed an issue I saw in #763 related to listenMqtt too.

Also added the docs to these new changes.
Thanks!

[Schmavery]

@7osCraft thanks a lot, I will review this soon.

@lequanglam you said here that you got blocked less when you mark as read? Should we turn this on by default?

[DanH42]

I use a custom user agent (pulled from my own web browser and updated periodically) but I don't automatically mark all messages as read, and I haven't been flagged in months. Instantly marking every single message as read 24/7 also sounds like bot behavior, so it's not something I'd want to happen by default.

I'll also mention that keeping track of appState made a huge difference in preventing security checkpoints, so I'd encourage anyone who's not using it to do so.

[HossamMohsen7]

Yes, auto marking as seen might be bot behaviour so that's why I made it false by default, but marking as delivered is done automatically by the browser or the app even if you leave it. Unless you go offline of course.

It also looks like some values in appState changes over time so I think we should do something about it.

[HossamMohsen7]

Another thing I do is sending typing indicators before every message. I might add that to the PR.

[Schmavery]

@7osCraft if you do the typing indicator change can you make it a separate PR please <3

[HossamMohsen7]

Sure 😃

[Schmavery]

I agree it would be cool to look into making appState easier to use or at least improving the docs around it so that it's less confusing

[Schmavery]

Looks mostly good, thanks for including the docs changes as well.
I left just a couple of small comments.

[HossamMohsen7]

Pushed some changes and fixes.

[Schmavery]

Great thanks!