Kapt: Move line metadata to .kaptMetadata external files (KT-22386)

Placing location table inside .java file triggers annotation processor to run on each line table modification (even when the stub declarations themselves are the same). So we move it to the separate file.

plugins/kapt3/kapt3-compiler/testData/converter/nestedClassesNonRootPackage.txt

@@ -1,6 +1,3 @@
-/**
- * @KaptMetadata
- */
 package test;
 
 import java.lang.System;
@@ -87,9 +84,6 @@ public final class A$B {
 
 ////////////////////
 
-/**
- * @KaptMetadata
- */
 package test;
 
 import java.lang.System;
@@ -125,9 +119,6 @@ public final class Experiment {
 
 ////////////////////
 
-/**
- * @KaptMetadata
- */
 package test;
 
 import java.lang.System;
@@ -159,9 +150,6 @@ public final class Foo {
 
 ////////////////////
 
-/**
- * @KaptMetadata
- */
 package test;
 
 import java.lang.System;
@@ -266,9 +254,6 @@ class JavaClass {
 
 ////////////////////
 
-/**
- * @KaptMetadata
- */
 package test;
 
 import java.lang.System;