Update schemas and resolve some warnings

migrations/20210603000000_initial.sql

@@ -136,9 +136,9 @@ CREATE TABLE reminders (
     set_by INT UNSIGNED,
 
     PRIMARY KEY (id),
-    FOREIGN KEY (message_id) REFERENCES messages(id) ON DELETE RESTRICT,
-    FOREIGN KEY (channel_id) REFERENCES channels(id) ON DELETE CASCADE,
-    FOREIGN KEY (set_by) REFERENCES users(id) ON DELETE SET NULL
+    CONSTRAINT `reminder_message_fk` FOREIGN KEY (message_id) REFERENCES messages(id) ON DELETE RESTRICT,
+    CONSTRAINT `reminder_channel_fk` FOREIGN KEY (channel_id) REFERENCES channels(id) ON DELETE CASCADE,
+    CONSTRAINT `reminder_user_fk` FOREIGN KEY (set_by) REFERENCES users(id) ON DELETE SET NULL
 );
 
 CREATE TRIGGER message_cleanup AFTER DELETE ON reminders
@@ -157,9 +157,9 @@ CREATE TABLE todos (
     value VARCHAR(2000) NOT NULL,
 
     PRIMARY KEY (id),
-    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE SET NULL,
-    FOREIGN KEY (guild_id) REFERENCES guilds(id) ON DELETE CASCADE,
-    FOREIGN KEY (channel_id) REFERENCES channels(id) ON DELETE SET NULL
+    CONSTRAINT todos_ibfk_5 FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE SET NULL,
+    CONSTRAINT todos_ibfk_4 FOREIGN KEY (guild_id) REFERENCES guilds(id) ON DELETE CASCADE,
+    CONSTRAINT todos_ibfk_3 FOREIGN KEY (channel_id) REFERENCES channels(id) ON DELETE SET NULL
 );
 
 CREATE TABLE command_restrictions (