added tables to mark messages as false negative (#27)

src/migrations/V6__false-banned.sql

@@ -0,0 +1,21 @@
+CREATE TABLE false_positive_users
+(
+    user_id BIGINT PRIMARY KEY
+        REFERENCES "user" (id) ON DELETE CASCADE
+);
+
+CREATE TABLE false_positive_messages
+(
+    chat_id    BIGINT NOT NULL,
+    message_id INT    NOT NULL,
+    PRIMARY KEY (chat_id, message_id),
+    FOREIGN KEY (chat_id, message_id) REFERENCES "message" (chat_id, message_id) ON DELETE CASCADE
+);
+
+CREATE TABLE false_negative_messages
+(
+    chat_id    BIGINT NOT NULL,
+    message_id INT    NOT NULL,
+    PRIMARY KEY (chat_id, message_id),
+    FOREIGN KEY (chat_id, message_id) REFERENCES "message" (chat_id, message_id) ON DELETE CASCADE
+);