[FIR] Fix inconsistent RETURN_TYPE_MISMATCH and TYPE_MISMATCH reporting on functions and properties

^KT-51203 Fixed

compiler/testData/diagnostics/tests/regressions/OutProjections.fir.kt

@@ -8,7 +8,7 @@ fun <T> f(expression : T) : G<out T> = G<T>()
 
 fun foo() : G<Point> {
   val p = Point()
-  return <!RETURN_TYPE_MISMATCH, TYPE_MISMATCH!>f<Point>(p)<!>
+  return <!RETURN_TYPE_MISMATCH!>f<Point>(p)<!>
 }
 
 class Out<out T>() {}

compiler/testData/diagnostics/tests/regressions/kt251.fir.kt

@@ -1,6 +1,6 @@
 class A() {
     var x: Int = 0
-        get() = "s"
+        get() = <!RETURN_TYPE_MISMATCH!>"s"<!>
         set(value: <!WRONG_SETTER_PARAMETER_TYPE!>String<!>) {
             field = <!ASSIGNMENT_TYPE_MISMATCH!>value<!>
         }
@@ -8,7 +8,7 @@ class A() {
         get(): <!WRONG_GETTER_RETURN_TYPE("kotlin/Int; kotlin/String")!>String<!> = "s"
     val z: Int
         get() {
-            return "s"
+            return <!RETURN_TYPE_MISMATCH!>"s"<!>
         }
 
     var a: Any = 1
@@ -27,7 +27,7 @@ class A() {
         }
     val e = 1
         get(): <!WRONG_GETTER_RETURN_TYPE!>String<!> {
-            return field
+            return <!RETURN_TYPE_MISMATCH!>field<!>
         }
 
 }