Format for Value renders incorrect escaping of quote characters in BigQuery

[graup]

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: PRQL/prql#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

#[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.

[brunal]

Another issue impl Display for EscapeQuotedString is that '\''' correctly gets parsed as 1 backlash and 1 single-quote, but displaying it returns '\'' which is invalid SQL.