Mark 1:1 chat as verified as soon as Alice is forward-verified
so Bob can already start sending Chat-Verified headers.
This way Alice and Bob can scan each other's QR codes
and even if all Secure-Join headers are dropped from the network,
still get forward verifications via QR-code scans
and backward verifications via Chat-Verified messages in 1:1 chat.
As per the comment in `receive_imf.rs`, `chat.protected` must be maintained regardless of the
`Config::VerifiedOneOnOneChats`. The only thing that mustn't be done if `VerifiedOneOnOneChats` is
unset (i.e. for non-supporting UIs) is marking chats as "protection broken" because this needs
showing the corresponding dialog to a user.
Before in some places it was correctly calculated by passing the "sent" timestamp to
`calc_sort_timestamp()`, but in other places just the system time was used. In some complex
scenarios like #5088 (restoration of a backup made before a contact verification) it led to wrong
sort timestamps of protection messages and also messages following by them.
But to reduce number of args passed to functions needing to calculate the sort timestamp, add
message timestamps to `struct MimeMessage` which is anyway passed everywhere.
Otherwise it looks like the message creating a protected group is not verified. For this, use
`sent_timestamp` of the received message as an upper limit of the sort timestamp (`msgs.timestamp`)
of the protection message. As the protection message is added to the chat earlier, this way its
timestamp is always less or eq than the received message's timestamp.
This esp. speeds up receive_imf a bit when we recreate the member list (recreate_member_list == true).
It's a preparation for https://github.com/deltachat/deltachat-core-rust/issues/3768, which will be a one-line-fix, but recreate the member list more often, so that we want to optimize this case a bit.
It also adds a benchmark for this case. It's not that easy to make the benchmark non-flaky, but by closing all other programs and locking the CPU to 1.5GHz it worked. It is consistently a few percent faster than ./without-optim:
```
Receive messages/Receive 100 Chat-Group-Member-{Added|Removed} messages
time: [52.257 ms 52.569 ms 52.941 ms]
change: [-3.5301% -2.6181% -1.6697%] (p = 0.00 < 0.05)
Performance has improved.
Found 7 outliers among 100 measurements (7.00%)
4 (4.00%) high mild
3 (3.00%) high severe
```
The state bob needs to maintain during a secure-join process when
exchanging messages used to be stored on the context. This means if
the process was killed this state was lost and the securejoin process
would fail. Moving this state into the database should help this.
This still only allows a single securejoin process at a time, this may
be relaxed in the future. For now any previous securejoin process
that was running is killed if a new one is started (this was already
the case).
This can remove some of the complexity around BobState handling: since
the state is in the database we can already make state interactions
transactional and correct. We no longer need the mutex around the
state handling. This means the BobStateHandle construct that was
handling the interactions between always having a valid state and
handling the mutex is no longer needed, resulting in some nice
simplifications.
Part of #2777.
