Add support for `DEFAULT`

[criccomini]

I'd like to be able to create tables like this:

CREATE TABLE `test_dataset.test_table_default` (
    test_string STRING DEFAULT "default_value"
)

When I do this right now, it executes, but the table doesn't seem to exist after.

See here for syntax:

https://cloud.google.com/bigquery/docs/default-values#set_default_values

[ohaibbq]

I've put up a first-pass of this functionality here https://github.com/goccy/go-zetasqlite/pull/211