Added api endpoints and tests

database/utils.go

@@ -0,0 +1,9 @@
+package database
+
+import "gorm.io/gorm"
+
+func Exists(tx *gorm.DB, query interface{}, args ...interface{}) bool {
+	var exists bool
+	tx.Where(query, args...).Select("count(*) > 0").Find(&exists)
+	return exists
+}