[IC] Refactor IC maps to reuse code and ensure consistency

The key changes include:
  - Top interface: `PersistentStorage`
  - Implementation:
      + `LazyStorage`
      + `InMemoryStorage`
  - Extended functionality:
      + `BasicMap`
      + `PersistentStorageAdapter`

 The remaining changes are small cleanups to adapt to the above key
 changes.

 Test: Existing tests (refactoring change)
 Bug: N/A (code cleanup)

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

@@ -154,7 +154,7 @@ open class IncrementalJsCache(
         }
         removeAllFromClassStorage(dirtyOutputClassesMap.getDirtyOutputClasses(), changesCollector)
         dirtySources.clear()
-        dirtyOutputClassesMap.clean()
+        dirtyOutputClassesMap.clear()
     }
 
     fun nonDirtyPackageParts(): Map<File, TranslationResultValue> =
@@ -447,13 +447,7 @@ private class PackageMetadataMap(
         storage[packageName] = newMetadata
     }
 
-    fun remove(packageName: String) {
-        storage.remove(packageName)
-    }
-
     fun keys() = storage.keys
 
-    operator fun get(packageName: String) = storage[packageName]
-
     override fun dumpValue(value: ByteArray): String = "Package metadata: ${value.md5()}"
 }