fix#3007
My approach is:
We don't download any messages from the spam folder anymore, and only download them if they were moved out. This means that is-it-spam logic only resides in spam_target_folder(). This has some implications, see the comments.
pytest-timeout already handles all deadlocks and is configurable with
--timeout option. With this change it is possible to disable timeout
with --timeout 0 to run tests on extremely slow connections.
Also change how NO response is treated. NO response means there is an
error moving/copying the messages. When there are no matching
messages, the response is "OK No matching messages, so nothing copied"
according to some RFC 9051 examples.
To create encrypted account with account manager, call
dc_accounts_add_closed_account(). Open this account with
dc_context_open() using the passphrase you want to use for encryption.
When application is loaded next time and account manager is created,
it will open all accounts that have no passphrase set. For encrypted
accounts dc_context_is_open() will return 0. To open them, call
dc_context_open() with the correct passphrase. After opening, call
dc_context_start_io() on this account or just dc_accounts_start_io()
to start all accounts that are not started yet.
Support for legacy SQLite-based backup format is removed in this
commit.
Also resultified `get_watched_folders`.
Python test `test_moved_markseen` is modified to test using incoming
message instead of BCC-self message, because BCC-self message is
detected immediately in the Inbox.
`imap` table maps Message-IDs to UIDs on the server. `dc_receive_imf`
no longer gets the UID of the message as an argument and does not
insert the folder and UID of the message into the `msgs`
table. `server_folder` and `server_uid` columns in `msgs` table are
deprecated.
MoveMsg and DeleteMsgOnImap jobs are removed. Now messages are moved
and deleted only in the `fetch_move_delete` procedure that consults
the `target` column of the `imap` table to determine where the message
should go.
Where the message should go is determined after prefetching by the
`imap::target_folder()` procedure. Messages are only downloaded once
they reach their target folder to avoid race conditions in multidevice
setting, such as:
1. One device trying to FETCH the message while the other tries to
MOVE it.
2. One device marking the message as \Seen in the Inbox while the
other has already copied unseen message to the Movebox and is going to
delete the \Seen message in the Inbox.
3. Device downloads the message from the Inbox while there are newer
messages in the Movebox placed there by the other device, thus
processing the messages out of order.
