Fix test-util fn all_dialects() to test all dialects actually

[unvalley]

This is for internal but some fixes may be for users.

In tests/sqlparser_common.rs (⚠️ linked page may freeze your browser), a lot of test cases depend on fn all_dialects() to test all dialects.
But this fn all_dialects() doesn't include MySqlDialect and BigQueryDialect currently.
So we should include those to all_dialects and fix failed test cases after changing.

Change all_dialects to add MySqlDialect and BigQueryDialect (src/test_utils.rs):

pub fn all_dialects() -> TestedDialects {
    TestedDialects {
        dialects: vec![
            Box::new(GenericDialect {}),
            Box::new(PostgreSqlDialect {}),
            Box::new(MsSqlDialect {}),
            Box::new(AnsiDialect {}),
            Box::new(SnowflakeDialect {}),
            Box::new(HiveDialect {}),
            Box::new(RedshiftSqlDialect {}),
            Box::new(MySqlDialect {}), // Added
            Box::new(BigQueryDialect {}), // Added
        ],
    }
}

Test results after changing above:

failures:
    parse_at_timezone
    parse_collate
    parse_collate_after_parens
    parse_delete_statement
    parse_delimited_identifiers
    parse_like
    parse_similar_to

test result: FAILED. 187 passed; 7 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.08s

error: test failed, to rerun pass '--test sqlparser_common'