feat: impl MCDatabase for mariadb

db/db-sqlx-maria/migrations/20210509151150_mcaptcha_notifications.sql

@@ -0,0 +1,19 @@
+-- Add migration script here
+CREATE TABLE IF NOT EXISTS mcaptcha_notifications (
+	id INT auto_increment,
+	PRIMARY KEY(id),
+
+	tx INT NOT NULL,
+	rx INT NOT NULL,
+	heading varchar(30) NOT NULL,
+	message varchar(250) NOT NULL,
+	-- todo: mv read -> read_notification 
+	read_notification BOOLEAN DEFAULT null,
+	received timestamp NOT NULL DEFAULT now(),
+
+	CONSTRAINT `fk_mcaptcha_mcaptcha_user_notifications_tx`
+		FOREIGN KEY (tx)
+		REFERENCES mcaptcha_users (ID)
+		ON DELETE CASCADE
+		ON UPDATE CASCADE
+);