Change parsing of annotations on block level expressions

Attach annotations to the closest prefix expression instead of
whole statement if no new line found after annotations

The motivation is for a simple annotated expression like '@ann x + y'
its syntax form must not change after prepending 'val z = ' just before it

compiler/testData/psi/annotation/at/blockLevelExpressions.kt

@@ -3,11 +3,21 @@ fun foo() {
     var x0 = foo0()
 
     @ann1
+    // comment
+    /* comment */
     x1 = foo1()
 
+    // many empty new lines
     @ann2
+
+
     x2 += foo2()
 
+    @ann21 @ann22
+
+    @ann23
+    x22 += foo22()
+
     for (i in 1..100) {
         @ann3
         x3 += foo3()