Format for Value renders incorrect escaping of quote characters in BigQuery

`impl fmt::Display for EscapeQuotedString` (which is used when formatting a Value expr) uses double quote character escaping (like `''` or `""`) which is a syntax error in BigQuery.

This was also reported in PRQL: https://github.com/PRQL/prql/issues/5099

To fix this, I think we need to make this method aware of the dialect. And potentially add a new supports rule (like supports_backslash_escaping?) If someone could chime in on the approach I can take a stab at it.

Here is a failing test case you can add to tests/sqlparser_bigquery.rs

```rs
#[test]
fn test_quote_escape() {
bigquery().verified_expr(r#"JSON '{"foo":"bar\'s"}'"#); // Wrong output: JSON '{"foo":"bar''s"}'
bigquery().verified_expr(r#"JSON "{\"foo\":\"bar's\"}""#); // Wrong output: JSON "{""foo"":""bar's""}"
}
```

Both of these are valid BigQuery syntax. They get parsed into the AST correctly but get formatted incorrectly.

Start with impl fmt::Display for EscapeQuotedString and the failing cases in tests/sqlparser_bigquery.rs. Run or add test_quote_escape to compare the formatted output for both valid BigQuery strings, then make the formatting dialect-aware so both cases retain valid escaping.

Written by the indexing model from the issue text.