FIR checker: skip error named reference if receiver is unresolved

Currently, FIR reports errors caused by previous resolution failure. For
example with unresolved `a` and `b` in code `a.b`, both `a` and `b` are
highlighted. FE1.0 only highlights `a` since it's the root cause. This
change applies this heuristics when reporting FirDiagnostics.

compiler/testData/diagnostics/tests/objects/ObjectsNested.fir.kt

@@ -26,4 +26,4 @@ val a = A
 val b = B
 val c = A.B
 val d = A.B.A
-val e = B.<!UNRESOLVED_REFERENCE!>A<!>.<!UNRESOLVED_REFERENCE!>B<!>
+val e = B.<!UNRESOLVED_REFERENCE!>A<!>.B