Use extension registry when unpacking serialized type alias

It's funny here that "extension" here means protobuf extensions
while initial issue is about extension function types

 #Fixed KT-22728

compiler/testData/loadJava/compiledKotlin/typealias/TypeAliasToExtension.kt

@@ -0,0 +1,7 @@
+package test
+
+class Foo<T>
+
+fun <P> foo(x: Foo<P>.() -> Unit) {}
+
+typealias MyHandler<P> = Foo<P>.() -> Unit

compiler/testData/loadJava/compiledKotlin/typealias/TypeAliasToExtension.txt

@@ -0,0 +1,8 @@
+package test
+
+public fun </*0*/ P> foo(/*0*/ x: test.Foo<P>.() -> kotlin.Unit): kotlin.Unit
+
+public final class Foo</*0*/ T> {
+    /*primary*/ public constructor Foo</*0*/ T>()
+}
+public typealias MyHandler</*0*/ P> = test.Foo<P>.() -> kotlin.Unit