Analyze Data Flow: Support properties with custom accessors

#KT-11994 In Progress

idea/testData/slicer/inflow/getterExpressionBody.kt

@@ -0,0 +1,8 @@
+// FLOW: IN
+
+val foo: Int
+    get() = 0
+
+fun test() {
+    val <caret>x = foo
+}