KT-45777: Clean up build cache tests for incremental compilation

- Clean up BuildCacheRelocationIT.testKotlinIncrementalCompilation
 - Delete BuildCacheIT.testKotlinCompileIncrementalBuildWithoutRelocation
   as it is already covered by the test in BuildCacheRelocationIT
 - Add BuildCacheRelocationIT.testKotlinIncrementalCompilation_withClasspathSnapshot
- Updated BuildCacheRelocationIT.testKotlinIncrementalCompilation_withClasspathSnapshot

build-common/src/org/jetbrains/kotlin/build/report/metrics/BuildAttribute.kt

@@ -16,6 +16,7 @@ enum class BuildAttributeKind : Serializable {
 }
 
 enum class BuildAttribute(val kind: BuildAttributeKind, val readableString: String) : Serializable {
+    CACHE_DIRECTORY_NOT_POPULATED(BuildAttributeKind.REBUILD_REASON, "Cache directory not populated"),
     NO_BUILD_HISTORY(BuildAttributeKind.REBUILD_REASON, "Build history file not found"),
     NO_ABI_SNAPSHOT(BuildAttributeKind.REBUILD_REASON, "ABI snapshot not found"),
     CLASSPATH_SNAPSHOT_NOT_FOUND(BuildAttributeKind.REBUILD_REASON, "Classpath snapshot not found"),

build-common/src/org/jetbrains/kotlin/incremental/LookupStorage.kt

@@ -288,13 +288,13 @@ data class LookupSymbol(val name: String, val scope: String) : Comparable<Lookup
 }
 
 /**
- * Wrapper of a [LookupMap] which tracks changes to the map after the initialization of this [TrackedLookupMap] instance, (unless
+ * Wrapper of a [LookupMap] which tracks changes to the map after the initialization of this [TrackedLookupMap] instance (unless
  * [trackChanges] is set to `false`).
  */
 private class TrackedLookupMap(private val lookupMap: LookupMap, private val trackChanges: Boolean) {
 
-    // Note that there may be multiple operations on the same key, and the following sets contain the *latest* differences with the original
-    // set of keys in the map. For example, if a key is added then removed, or vice versa, it will not be present in either set.
+    // Note that there may be multiple operations on the same key, and the following sets contain the *aggregated* differences with the
+    // original set of keys in the map. For example, if a key is added then removed, or vice versa, it will not be present in either set.
     val addedKeys = if (trackChanges) mutableSetOf<LookupSymbolKey>() else null
     val removedKeys = if (trackChanges) mutableSetOf<LookupSymbolKey>() else null