Option for product.

Column	Type	Constraint	Description
shop	TEXT	PRIMARY KEY	Shop ID. (shop.username)
id	INTEGERL		Identifier.
group_id	INTEGER	NOT NULL	Belonged group id. (group.id).
charge	INTEGER	NOT NULL	Surcharge of the option.

CREATE TABLE option(
shop       TEXT,
id         INTEGER,
group_id   INTEGER  NOT NULL,
charge     INTEGER  NOT NULL,
PRIMARY KEY(shop, id)
);

Multilingualized name of option.

Column	Type	Constraint	Description
shop	TEXT	PRIMARY KEY	Shop ID. (shop.username)
option_id	INTEGER		Option ID. (option.id)
lang	TEXT		Language key.
name	TEXT	NOT NULL	Option name.

CREATE TABLE option_content(
shop       TEXT,
option_id  INTEGER,
lang       TEXT,
name       TEXT     NOT NULL,
PRIMARY KEY(shop, lang, option_id)
);