SI-7331, SI-6843, SI-7731, parser entry point refactoring

This commits fixes following bugs:

* SI-7331 tb.parse returns unpositioned trees
* SI-6843 better error reporting for quasiquotes
* SI-7731 CannotHaveAttrs has inconsistent handling of setPos and setType

And additionaly refactors parser entry points to make parsing stats consistent across repl, toolbox, script runner and quasiquotes.