[kotlinp] Split :tools:kotlinp into "common" and "jvm" subprojects

The "common" subproject keeps only backend-neutral logic and depends
only on :kotlinx-metadata library. It takes the name of the former
project - :tools:kotlinp

The "jvm" subproject depends on the "common" one and also depends
on :kotlinx-metadata-jvm. It gets the new name - :tools:kotlinp-jvm

There is a lot of touched files in this commit. The majority of them
is just moved files (tests, test data, etc).

Only the following files were actually modified:
  .space/CODEOWNERS
  build.gradle.kts
  libraries/tools/abi-comparator/build.gradle.kts
  libraries/tools/kotlinp/build.gradle.kts
  libraries/tools/kotlinp/jvm/build.gradle.kts
  plugins/kapt3/kapt3-compiler/build.gradle.kts
  settings.gradle

 ^KT-62340

libraries/tools/kotlinp/jvm/testData/NestedClasses.txt

@@ -0,0 +1,80 @@
+// A.class
+// ------------------------------------------
+public abstract interface A : kotlin/Any {
+
+  // companion object: D
+
+  // nested class: B
+
+  // nested class: D
+
+  // module name: test-module
+}
+// A$B.class
+// ------------------------------------------
+public abstract interface A.B : kotlin/Any {
+
+  // nested class: C
+
+  // module name: test-module
+}
+// A$B$C.class
+// ------------------------------------------
+public abstract interface A.B.C : kotlin/Any {
+
+  // module name: test-module
+}
+// A$D.class
+// ------------------------------------------
+public final companion object A.D : kotlin/Any {
+
+  // signature: <init>()V
+  private constructor()
+
+  // nested class: E
+
+  // nested class: F
+
+  // module name: test-module
+}
+// A$D$E.class
+// ------------------------------------------
+public final enum class A.D.E : kotlin/Enum<A.D.E> {
+
+  // signature: <init>(Ljava/lang/String;I)V
+  private constructor()
+
+  E1,
+
+  E2,
+
+  // module name: test-module
+
+  // has Enum.entries
+}
+// A$D$F.class
+// ------------------------------------------
+public sealed class A.D.F : kotlin/Any {
+
+  // signature: <init>()V
+  protected constructor()
+
+  // nested class: G
+
+  // sealed subclass: A.D.F.G
+
+  // module name: test-module
+}
+// A$D$F$G.class
+// ------------------------------------------
+public final class A.D.F.G : A.D.F {
+
+  // signature: <init>()V
+  public constructor()
+
+  // module name: test-module
+}
+// META-INF/test-module.kotlin_module
+// ------------------------------------------
+module {
+}