Due to possible data races configuration discovery might fail. So far,
it happened silently and we used so-called default one. This
configuration is unaware of specific implicit imports, receivers, base
class, etc. Hence, broken highlighting and navigation.
This commit introduces the following changes:
1. Having default configuration for building `FirScript` is no longer an
option. Missing configuration means error reported via exception.
2. Every configuration usage is now logged in DEBUG mode.
Troubleshooting becomes easier.
^KT-60193 fixed
Andrei Klunnyi
c9eebffbfa