First part of options refactoring (#6428)

First part of options refactoring (#6428)

This PR does a first round of refactoring and gets rid of a significant portion of generated code. In particular

- it removes options::optionName.wasSetByUser() (we still have Options::wasSetByUser())
- it removes options::optionName.set() (we still have Options::set())
- it removes options::optionName.getName() in favor of options::optionName.name
- it removes the specializations of Options::assign() and Options::assignBool() from the headers
- it eliminates runHandlerAndPredicates() and runBoolPredicates()

The removed methods are only used in few places with are changed to using Options::current().X() instead.

In the future, we also want to get rid of options::optionName() and use Options::operator[]() instead, and furthermore not use Options::current() but use the options from the Env object. This PR already adds Env::getOption() as a shorthand for Env::getOptions()[...] and uses it as a proof of concept within SmtEngine.