FIR DFA: use class enter node as data flow source for members

Also fix graphs for enums with specialized entries - since we don't
create property subgraphs for FirEnumEntry, there is no body to insert
AnonymousObjectEnterNode, AnonymousObjectExitNode, and
AnonymousObjectExpressionExitNode into.

compiler/fir/analysis-tests/testData/resolve/cfg/annotatedLocalClass.dot

@@ -79,13 +79,12 @@ digraph annotatedLocalClass_kt {
     16 -> {17} [style=dotted];
     17 -> {18} [style=dotted];
     18 -> {19};
-    18 -> {25} [color=red];
-    19 -> {20};
-    19 -> {23} [color=green];
+    19 -> {20 23};
     19 -> {23} [style=dashed];
     20 -> {21};
     21 -> {22};
     23 -> {24} [color=green];
+    23 -> {25} [color=red];
     24 -> {25} [color=green];
     24 -> {25} [style=dashed];
     25 -> {26};