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

^KT-51203 Fixed

compiler/testData/diagnostics/tests/functionLiterals/missedTypeMismatch.fir.kt

@@ -11,8 +11,8 @@ fun main() {
 
     val a0: () -> Int = <!INITIALIZER_TYPE_MISMATCH!>fun(): String = "1"<!>
     val a1: () -> Int = <!INITIALIZER_TYPE_MISMATCH!>(fun() = "1")<!>
-    val a2: () -> Unit = (fun() = "1")
-    val a3: Unit = <!INITIALIZER_TYPE_MISMATCH!>(fun() = "1")<!>
+    val a2: () -> Unit = (fun() = <!RETURN_TYPE_MISMATCH!>"1"<!>)
+    val a3: Unit = <!INITIALIZER_TYPE_MISMATCH!>(fun() = <!RETURN_TYPE_MISMATCH!>"1"<!>)<!>
     val a4 = (fun() = "1")
     val a5 = (fun(): String = "1")
     val a6: () -> Int = (fun() = 1)

compiler/testData/diagnostics/tests/functionLiterals/return/IfWithoutElseWithExplicitType.fir.kt

@@ -5,7 +5,7 @@ val a: () -> Int = <!INITIALIZER_TYPE_MISMATCH!>l@ {
 }<!>
 
 val b: () -> Unit = l@ {
-    if (flag) return@l 4
+    if (flag) return@l <!RETURN_TYPE_MISMATCH!>4<!>
 }
 
 val c: () -> Any = l@ {

compiler/testData/diagnostics/tests/functionLiterals/return/LocalReturnSecondUnit.fir.kt

@@ -1,6 +0,0 @@
-val flag = true
-
-val a = b@ {
-    if (flag) return@b 4
-    return@b
-}

compiler/testData/diagnostics/tests/functionLiterals/return/LocalReturnSecondUnit.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 val flag = true
 
 val a = b@ {

compiler/testData/diagnostics/tests/functionLiterals/return/LocalReturnsWithExplicitReturnType.fir.kt

@@ -1,6 +1,6 @@
 fun test(a: Int) {
     run<Int>f@{
-      if (a > 0) return@f <!ARGUMENT_TYPE_MISMATCH!>""<!>
+      if (a > 0) return@f <!ARGUMENT_TYPE_MISMATCH, RETURN_TYPE_MISMATCH!>""<!>
       return@f 1
     }