[FIR] Implement ASSIGNMENT_TYPE_MISMATCH, RESULT_TYPE_MISMATCH diagnostics, fix tests

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/overrides.fir.kt

@@ -34,8 +34,8 @@ fun foo(c: C) {
     c.z checkType { _<String>() }
 
     c.y = ""
-    c.y = 1
+    c.y = <!ASSIGNMENT_TYPE_MISMATCH!>1<!>
 
     c.z = ""
-    c.z = 1
+    c.z = <!ASSIGNMENT_TYPE_MISMATCH!>1<!>
 }

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/vars.fir.kt

@@ -14,8 +14,8 @@ fun foo() {
     noSetter checkType { _<Int>() }
 
     x = 1
-    x = ""
+    x = <!ASSIGNMENT_TYPE_MISMATCH!>""<!>
 
     noSetter = 2
-    noSetter = ""
+    noSetter = <!ASSIGNMENT_TYPE_MISMATCH!>""<!>
 }