[FIR] CFG: drop redundant edges

Edges from class to its functions and nested classes are redundant
and lead to extra resolution work in lazy resolve mode

^KT-59600 Fixed

compiler/fir/analysis-tests/testData/resolve/cfg/nestedClass.kt

@@ -0,0 +1,12 @@
+// !DUMP_CFG
+class OuterClass {
+    fun outerFunction() {}
+    val outerProperty = 1
+    val outerProperty2 = outerProperty
+
+    class NestedClass {
+        fun nestedFUnction() {}
+        val nestedProperty = 1
+        val nestedProperty2 = nestedProperty
+    }
+}