KT-45777: Reorganize unit test data for classpath snapshot feature

to make it easier to add more tests in the next commits.

- Add unit tests for constants and inline functions

Also add tests for different kinds of Kotlin classes: CLASS,
FILE_FACADE, MULTIFILE_CLASS.

-Add unit test for nested classes

Also remove the existing integration test for nested classes to keep the
integration tests focused on the key scenarios while unit tests will
cover the corner cases.

Ignore inline functions that are private

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/IncrementalJavaChangeIT.kt

@@ -55,18 +55,6 @@ class IncrementalJavaChangeClasspathSnapshotIT : IncrementalJavaChangeDefaultIT(
             }
         )
     }
-
-    @Test
-    fun testAddingInnerClass() {
-        doTest(
-            "A.kt",
-            { content: String -> content.substringBeforeLast("}") + " class InnerClass }" },
-            assertResults = {
-                assertTasksExecuted(":lib:compileKotlin", ":app:compileKotlin")
-                assertCompiledKotlinFiles(project.projectDir.getFilesByNames("AAA.kt", "AA.kt", "BB.kt", "A.kt", "B.kt"))
-            }
-        )
-    }
 }
 
 class IncrementalJavaChangePreciseIT : IncrementalCompilationJavaChangesBase(usePreciseJavaTracking = true) {