IDEA-95898 Gradle based projects should offer Auto-Import as Maven projects do

GradleJarManager correctly performs bulk 'import jars' operation by separating jars by library
IDEA-95898 Gradle based projects should offer Auto-Import as Maven projects do

Revive gradle tests after auto-import introduction (change service dependencies and api)
API for conformant stub processing skip methods
Cleaner API for light token visiting
Stub processing skip in Java code blocks optimized