Support sqlalchemy style parameterized queries

[andharris]

I would like to be able to use the sqlalchemy style parameterized queries within this dialect.

from sqlalchemy import text

result = connection.execute(text("SELECT * FROM users WHERE id = :user_id"), user_id=12)

It seems the current implementation only supports pyformat style

result = connection.execute("SELECT * FROM users WHERE id = %(user_id)s", user_id=12)