UL properties supports JvmSynthetic annotation for get: and set: modifiers

(+small refactoring)
Fixed #KT-34973

compiler/testData/asJava/ultraLightClasses/jvmSyntheticForAccessors.java

@@ -0,0 +1,9 @@
+public final class X /* X*/ {
+  @null()
+  public  X();
+
+  public final int getW();
+
+  public final void setV(int);
+
+}

compiler/testData/asJava/ultraLightClasses/jvmSyntheticForAccessors.kt

@@ -0,0 +1,9 @@
+
+
+class X {
+    @get:JvmSynthetic
+    var v = 1
+
+    @set:JvmSynthetic
+    var w = 1
+}