Fixed selection in case of empty class body

#KT-30597 Fixed

idea/testData/wordSelection/Class/0.kt

@@ -0,0 +1,3 @@
+class SimpleClass {
+    <caret>
+}

idea/testData/wordSelection/Class/1.kt

@@ -0,0 +1,3 @@
+class SimpleClass <selection>{
+    <caret>
+}</selection>

idea/testData/wordSelection/Class/2.kt

@@ -0,0 +1,3 @@
+<selection>class SimpleClass {
+    <caret>
+}</selection>