feat: log the number of read/written bytes on IMAP stream read error

[link2xt]

LoggingStream is a wrapper for IMAP/SMTP/HTTP session streams. Originally I started building it with the idea to debug #6477 and similar issues where IMAP loop gets stuck with the hope that right before the loop gets stuck or even continuously there are socket errors like a read timeout that are not treated correctly.

This can later be expanded to collect the metrics in the database, display them in the connectivity view, but not in this PR. Same for logging the write or flush errors, I have not added it for now because they are less common.

[link2xt]

First commit currently adds peer_addr method to SessionStream trait. I also created chatmail/async-imap#120 that may be useful to get access to SessionStream of IMAP session and then to peer_addr, e.g. to log it or add current address to connectivity view.

[link2xt]

Logs look like this:

Read error on stream a.b.c.d:993 after reading 98624 and writing 1074 bytes: timed out.
src/scheduler.rs:422: Failed inbox fetch_idle: fetch_move_delete: fetch_new_messages: fetch_many_msgs: Failed to process IMAP FETCH result: io: timed out: timed out.

Now right before the message about IMAP timeout we get a log message with the peer address and the number of read and written bytes.