Extract control flow analysis to separate module

Extract a service interface out of ControlFlowInformationProviderImpl
and register its implementation in two "leaf" modules: 'cli',
'idea-core'.

This improves parallel build, since a lot of modules depend on
'frontend' but only these two modules reference the implementation and
thus depend on the full CFA implementation now.

settings.gradle

@@ -90,6 +90,7 @@ include ":benchmarks",
         ":compiler:frontend",
         ":compiler:frontend.common",
         ":compiler:frontend.java",
+        ":compiler:frontend:cfg",
         ":kotlin-compiler-runner",
         ":compiler:cli-common",
         ":compiler:ir.tree",