Fix placeholder sequence

[ycalansy]

This pull request fixes the issue of incorrect positional arguments.

Example:

StatementBuilder = StatementBuilder.PlaceholderFormat(Dollar)
cteBuilder := Select("*").From("users").Where("id = ?", 1)
queryBuilder := Select("*").From("base").Where("name = ?", "John Doe").With("base", cteBuilder)
sql, args, err := queryBuilder.ToSql()

When there are placeholders in both the CTE and the main query, the current master branch renders the above query as follows, which incorrectly reuses position number 1.

WITH base AS (SELECT * FROM users WHERE id = $1) SELECT * FROM base WHERE name = $1