IR: remove isFromJava check from isOverridableMemberOrAccessor

This is needed because in case a static member is inherited via a Kotlin
class (class C in the newly added test), its origin becomes
FAKE_OVERRIDE which is technically not Java anymore. After this change,
we'll build fake overrides for static members from superclasses
regardless of whether they come from Java or Kotlin.

Also, move the previous logic of
isOverridableFunction/isOverridableProperty to the only call site at
IdSignatureFactory.

 #KT-65589 Fixed

compiler/testData/codegen/box/javaInterop/statics/jkkjk.kt

@@ -0,0 +1,26 @@
+// TARGET_BACKEND: JVM
+// FILE: A.java
+public class A {
+    public static String o = "O";
+
+    public static String k() {
+        return "K";
+    }
+}
+
+// FILE: B.kt
+open class B : A()
+
+// FILE: C.kt
+open class C : B()
+
+// FILE: D.java
+public class D extends C {}
+
+// FILE: E.kt
+class E : D() {
+    fun g(): String = o + k()
+}
+
+// FILE: box.kt
+fun box(): String = E().g()