Support for new double colon expressions in type checker

Despite the fact that the LHS of a double colon expression is now KtExpression
instead of KtUserType, we must still consider it a type for callable references
to work. Extract and reuse relevant parts of QualifiedExpressionResolver and
TypeResolver to support this behavior

compiler/testData/diagnostics/tests/callableReference/classVsPackage.kt

@@ -0,0 +1,24 @@
+// MODULE: m1
+// FILE: 1.kt
+
+package a
+
+class b {
+    class c
+}
+
+// MODULE: m2
+// FILE: 2.kt
+
+package a.b
+
+class c {
+    fun foo() {}
+}
+
+// MODULE: m3(m1, m2)
+// FILE: test.kt
+
+package test
+
+fun test() = a.b.c::foo