Escape string literals by default

[RobinClowers]

I believe Kysely should escape string literals by default, or at least provide an option to handle this. I brought this up before, and escaping was added to identifiers, but I don't believe it was applied to literals.

[koskimas]

As a clarification to anyone reading this, Kysely sends all user input as parameters and there is no chance of SQL injection. Parameters are never concatenated to the SQL.

This issue is about the explicit sql.lit function that allows you to concatenate string values to SQL.