remove imaplib dependency

[akvadrako]

I felt like taking a stab at this. It seems to work, though I've only tested against Dovecot. I added a livetest.sh file to automate this with podman.

Basically, I incorporated all the calls from imaplib that imapclient was using into IMAPClient or a new conn.IMAP4 class for the low-level stuff. I divided _command_and_check into 2 versions:

1. _uid_command_and_check -> just calls _simple_command, optionally with UID prefix.
2. _subcommand_and_check -> wraps an old imaplib method. No UID support.

It should be easy to do a bit more refactoring on a command-by-command basis, merging the old _cmd_XXX() call (that's from imaplib) into the imapclient parent method. Most of the work might actually be updating the unit tests.

There are a few more things to note. It seems like ACCEPT=UTF8 support was broken, since imaplib.IMAP4.enable() wasn't be called - that's where the magic happens. So I just removed that stuff for now. Also, there were a few calls imaplib supported that client doesn't - like get/set annotations. I left those in as private methods.

I'm open to any feedback.

[mjs]

Thanks for this. It looks promising.

I've had a crazy week so I haven't been able to look at the changes properly yet but I will soon.