FIR: Rework checking dispatch receivers applicability

Using `ownerLookupTag` might be wrong in case of private constuctors
 of inner classes: their owner is an Inner class, but expected
 dispach receiver is Outer

compiler/testData/diagnostics/tests/visibility/innerClassDelegatingConstructorCallToPrivate.kt

@@ -0,0 +1,10 @@
+// FIR_IDENTICAL
+// SKIP_TXT
+
+val w: Int = 2
+
+class Outer {
+    private inner class Inner private constructor(x: Int) {
+        constructor() : this(w)
+    }
+}