core: group link connection request uri data; automatically join groups over group links (#1275)

src/Simplex/Chat/Migrations/chat_schema.sql

@@ -257,6 +257,7 @@ CREATE TABLE connections(
   conn_req_inv BLOB,
   local_alias DEFAULT '' CHECK(local_alias NOT NULL),
   via_group_link INTEGER DEFAULT 0 CHECK(via_group_link NOT NULL),
+  group_link_id BLOB,
   FOREIGN KEY(snd_file_id, connection_id)
   REFERENCES snd_files(file_id, connection_id)
   ON DELETE CASCADE
@@ -273,6 +274,7 @@ CREATE TABLE user_contact_links(
   auto_reply_msg_content TEXT DEFAULT NULL,
   group_id INTEGER REFERENCES groups ON DELETE CASCADE,
   auto_accept_incognito INTEGER DEFAULT 0 CHECK(auto_accept_incognito NOT NULL),
+  group_link_id BLOB,
   UNIQUE(user_id, local_display_name)
 );
 CREATE TABLE contact_requests(