Delete messages more thoroughly (and at all) (#2114)

- Make sure delete_expired_messages and housekeeping runs once a day
- delete more info about messages when putting them to trash (esp. also
delete txt_raw, from_id and to_id as we don't need those anymore, so
they are data that was unnecessarily kept)

fix #1926, fix #2090

Also:

* Nicer test_utils: add send_text() and print_chat()

* Adapt ephemeral messages for testing (make them accurate to the second)

* Add test for ephemeral messages

* Make pop_sent_msg() really pop the last sent message

src/chat.rs

@@ -1040,7 +1040,7 @@ impl Chat {
         };
         let ephemeral_timestamp = match ephemeral_timer {
             EphemeralTimer::Disabled => 0,
-            EphemeralTimer::Enabled { duration } => timestamp + i64::from(duration),
+            EphemeralTimer::Enabled { duration } => time() + i64::from(duration),
         };
 
         // add message to the database