[K/N] Consolidate forward declarations handling

This is refactoring in preparation for KT-59764.
Names and layout of forward declarations related classes
was copy-pasted many times over compiler code.

Implementing KT-59764 would require copy-pasting it two more times.
So instead of doing this it was put in single place.

No behaviour changes intended in this commit.

compiler/fir/entrypoint/build.gradle.kts

@@ -16,6 +16,7 @@ dependencies {
     api(project(":compiler:fir:checkers:checkers.native"))
     api(project(":js:js.frontend"))
 
+    implementation(project(":core:compiler.common.native"))
     implementation(project(":compiler:fir:resolve"))
     implementation(project(":compiler:fir:fir-serialization"))
     implementation(project(":compiler:fir:fir2ir:jvm-backend"))