[FIR] Calculate property setters visibilities for intersections properly

Basically, just calculate them the same
way it's done for other members.

`chooseIntersectionVisibilityForSymbolsOrNull`
is named like this to prevent a JVM clash.

^KT-66046 Fixed

compiler/testData/diagnostics/tests/intersectedVisibilitiesForAbstractPropertyAccessors.fir.kt

@@ -1,22 +0,0 @@
-// ISSUE: KT-66046
-
-abstract class I1 {
-    abstract var a: Int
-        protected set
-}
-
-interface I2 {
-    var a: Int
-}
-
-abstract class <!CANNOT_WEAKEN_ACCESS_PRIVILEGE!>C<!> : I1(), I2
-
-abstract class I3 {
-    protected abstract fun foo(): Int
-}
-
-interface I4 {
-    fun foo(): Int
-}
-
-abstract class B : I3(), I4

compiler/testData/diagnostics/tests/intersectedVisibilitiesForAbstractPropertyAccessors.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // ISSUE: KT-66046
 
 abstract class I1 {