This adds support for sequences to Genji. For now, only sequence creation and use is supported, dropping or modifying a sequence will be added later.
To create a sequence:
```sql
CREATE SEQUENCE seq INCREMENT BY 10 MINVALUE 100 NO MAXVALUE START 500 CACHE 32 CYCLE;
```
Table and index information is now stored the same way, with minimal data:
sql: query used to create the table / index
table_name / index_name
store_name
