Move MetadataPartProvider to deserialization.common

To make it possible to use it in FIR compiler

core/deserialization.common/src/org/jetbrains/kotlin/serialization/deserialization/MetadataPartProvider.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.serialization.deserialization
+
+interface MetadataPartProvider {
+    /**
+     * @return simple names of .kotlin_metadata files that store data for top level declarations in the package with the given FQ name
+     */
+    fun findMetadataPackageParts(packageFqName: String): List<String>
+
+    object Empty : MetadataPartProvider {
+        override fun findMetadataPackageParts(packageFqName: String): List<String> = emptyList()
+    }
+}