Introduce "use expression body" inspection #KT-16063 Fixed

Converted from the relevant intention
Reported cases: one-liners, whens
Also, more exact caret detection in local inspection tests

idea/testData/quickfix/addStarProjections/cast/changeFunctionalToStarProjection.kt

@@ -1,5 +1,4 @@
 // "class org.jetbrains.kotlin.idea.quickfix.ChangeToStarProjectionFix" "false"
-// ACTION: Convert to expression body
 
 class Constructor<out T>(val x: T)
 

idea/testData/quickfix/addStarProjections/cast/uncheckedCastOnTypeParameter.kt

@@ -1,5 +1,4 @@
 // "class org.jetbrains.kotlin.idea.quickfix.ChangeToStarProjectionFix" "false"
-// ACTION: Convert to expression body
 fun <T> get(column: String, map: Map<String, Any>): T {
     return map[column] as <caret>T
 }