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.

compiler/cli/build.gradle.kts

@@ -8,6 +8,7 @@ dependencies {
     compile(project(":compiler:cli-common"))
     compile(project(":compiler:frontend"))
     compile(project(":compiler:frontend.java"))
+    compile(project(":compiler:frontend:cfg"))
     compile(project(":compiler:backend-common"))
     compile(project(":compiler:backend"))
     compile(project(":compiler:backend.jvm"))