fix: Correctly delete unneeded messages on the server; Remove "Delete Messages from Server" (delete_server_after) config option (#8240)

Fix https://github.com/chatmail/core/issues/8195
Supersedes https://github.com/chatmail/core/pull/8217

The most interesting change is in `delete_expired_imap_messages()`
because there, messages are marked for deletion on single-device
chatmail profiles.

The logic in `delete_expired_imap_messages()` was wrong before, and
pre-messages were not deleted at all. This is fixed by also querying
`pre_rfc724_mid` in addition to `rfc724_mid` from the `msgs` table.
In order not to make the SQL statement too complex, I split it into two.

WRT tests:
- `test_immediate_autodelete()` tests the auto-deletion;
`test_imap_autodelete_fully_downloaded_msg()` tests that even for a
message that is split into pre- and post-message, both messages are
deleted.
- A lot of tests test that if bcc_self is on, messages are not
auto-deleted. E.g. `test_one_account_send_bcc_setting()` and
`test_markseen_message_and_mdn()` relies on the fact that messages stay
on the server when bcc_self is on.
- Unfortunately, it is not possible to test that messages are only
deleted for chatmail servers, because we don't have any tests that use a
non-chatmail server.

deltachat-repl/src/cmdline.rs

@@ -1236,11 +1236,9 @@ pub async fn cmdline(context: Context, line: &str, chat_id: &mut ChatId) -> Resu
         "estimatedeletion" => {
             ensure!(!arg1.is_empty(), "Argument <seconds> missing");
             let seconds = arg1.parse()?;
-            let device_cnt = message::estimate_deletion_cnt(&context, false, seconds).await?;
-            let server_cnt = message::estimate_deletion_cnt(&context, true, seconds).await?;
-            println!(
-                "estimated count of messages older than {seconds} seconds:\non device: {device_cnt}\non server: {server_cnt}"
-            );
+            let from_server = false;
+            let device_cnt = message::estimate_deletion_cnt(&context, from_server, seconds).await?;
+            println!("estimated count of messages older than {seconds} seconds: {device_cnt}");
         }
         "" => (),
         _ => bail!("Unknown command: \"{arg0}\" type ? for help."),