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
Previously, expressions and params were evaluated
during the planning phase. This change builds the query
plan without evaluating params and expressions
which are then evaluated only during the execution phase.
By default, if there is a conflict when inserting a document,
we abort the current statement. Are considered conflicts
any error returned by duplicate primary keys or unique
constraint violations. The ON CONFLICT clause only
supports the DO NOTHING action, which returns no error.
