[FIR] Check conflicting overloads via scopes

Scopes may return private symbols from
supertypes, they should not clash with
symbols from the current class.

For example, see:
`FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated.FakeOverride#testPrivateFakeOverrides1`

Lombok shouldn't generate functions if the
user has defined explicit ones.

In K1 generated functions are not really
added to the declared members scope.

^KT-61243 Fixed

compiler/testData/diagnostics/tests/redeclarations/EnumName.txt

@@ -3,6 +3,10 @@ package
 public final enum class A : kotlin.Enum<A> {
     enum entry name
 
+    enum entry ordinal
+
+    enum entry entries
+
     private constructor A()
     @kotlin.internal.IntrinsicConstEvaluation public final override /*1*/ /*fake_override*/ val name: kotlin.String
     public final override /*1*/ /*fake_override*/ val ordinal: kotlin.Int