text: CREATE TYPE TASK_TYPE AS ENUM ('idle', 'walk', 'defend', 'gather_sticks', 'chop_tree', 'welcome_ability');
  CREATE TABLE tasks (
      id BIGSERIAL PRIMARY KEY,
      unit_id BIGINT NOT NULL REFERENCES units (id) ON DELETE CASCADE,
      task_type TASK_TYPE NOT NULL,
      x INT NOT NULL,
      y INT NOT NULL,
      start_time TIMESTAMP NOT NULL DEFAULT NOW()
  );