Currently `Chat.send_msg()` modifies the source message and returns another message object
equivalent to the source one. That's how it works in the core and thus in Python bindings too.
We do not want all_work_done() to return true immediately
after calling start_io(), but only when connection goes idle.
"Connected" state is set immediately after connecting to the server,
but it does not mean there is nothing to do.
This change make all_work_done() return false
from the Connected state and introduces a new Idle
connectivity state that is only set before connection
actually goes idle. For idle state all_work_done() returns true.
From the user point of view both old Connected state
and new Idle state look the same.
We already synchronise status/footer when we see a self-sent message with a Chat-Version
header. Would be nice to do the same for display name.
But let's do it the same way as for `Config::{MdnsEnabled,ShowEmails}`. Otherwise, if we sync the
display name using the "From" header, smth like `Param::StatusTimestamp` is needed then to reject
outdated display names. Also this timestamp needs to be updated when `Config::Displayname` is set
locally. Also this wouldn't work if system time isn't synchronised on devices. Also using multiple
approaches to sync different config values would lead to more code and bugs while having almost no
value -- using "From" only saves some bytes and allows to sync some things w/o the synchronisation
itself to be enabled. But the latter also can be a downside -- if it's usual synchonisation, you can
(potentially) disable it and share the same email account across people in some organisation
allowing them to have different display names. With using "From" for synchronisation such a
capability definitely requires a new config option.
Before, it was shown by UI when the chat is empty, however, in case of
verified groups, this is never the case any longer as the 'e2ee now
guaranteed' is always added.
This is needed to test periodic re-gossiping in existing chats.
Also add a test for verified groups on that even if "member added" message is missed by a device of
newly added member, after re-gossiping Autocrypt keys to the group it successfully learns these keys
and marks other members as verified.
1:1 chat may be blocked while the contact is not
if 1:1 chat was created as a result of scanning
a verified group join QR code with the contact
as the inviter. In this case 1:1 chat is blocked to hide it
while the contact is unblocked.
iequidoo