core: timed messages (#1561)

* docs: disappearing messages rfc

* change schema

* word

* wip

* wip

* todos

* todos

* remove cancel, refactor

* revert prefs

* CITimed

* schema

* time on send direct

* time on send group

* add ttl to msg container, refactor

* timed on receive

* time on read

* getTimedItems, fix tests

* mark read in terminal - view, input, output, fix tests

* refactor

* comment

* util

* insert atomically

* refactor

* use guards

* refactor startTimedItemThread

Co-authored-by: Evgeny Poberezkin <2769109+epoberezkin@users.noreply.github.com>

src/Simplex/Chat/Migrations/chat_schema.sql

@@ -365,7 +365,9 @@ CREATE TABLE chat_items(
   quoted_content TEXT,
   quoted_sent INTEGER,
   quoted_member_id BLOB,
-  item_edited INTEGER
+  item_edited INTEGER,
+  timed_ttl INTEGER,
+  timed_delete_at TEXT
 );
 CREATE TABLE chat_item_messages(
   chat_item_id INTEGER NOT NULL REFERENCES chat_items ON DELETE CASCADE,
@@ -456,3 +458,4 @@ CREATE UNIQUE INDEX idx_snd_files_last_inline_msg_delivery_id ON snd_files(
 CREATE INDEX idx_messages_connection_id ON messages(connection_id);
 CREATE INDEX idx_chat_items_group_member_id ON chat_items(group_member_id);
 CREATE INDEX idx_chat_items_contact_id ON chat_items(contact_id);
+CREATE INDEX idx_chat_items_timed_delete_at ON chat_items(timed_delete_at);