[FIR] Implement ASSIGNMENT_TYPE_MISMATCH, RESULT_TYPE_MISMATCH diagnostics, fix tests

compiler/fir/analysis-tests/testData/resolve/extendedCheckers/CanBeValChecker.kt

@@ -107,7 +107,7 @@ fun foo() {
     if (bool) <!ASSIGNED_VALUE_IS_NEVER_READ!>a<!> = 4 else <!ASSIGNED_VALUE_IS_NEVER_READ!>a<!> = 42
     val <!VARIABLE_NEVER_READ!>b<!>: String
 
-    <!ASSIGNED_VALUE_IS_NEVER_READ!>b<!> = false
+    <!ASSIGNED_VALUE_IS_NEVER_READ!>b<!> = <!ASSIGNMENT_TYPE_MISMATCH!>false<!>
 }
 
 fun cycles() {

compiler/fir/analysis-tests/testData/resolve/extendedCheckers/canBeReplacedWithOperatorAssignment/mutableList.kt

@@ -5,5 +5,5 @@ fun foo() {
     // now, Idea hightlights this code like error (cuz listVar
     // is mutable and listVar + 4 is immutable) and like warning
     // (cuz can be replaced with +=)
-    <!ASSIGNED_VALUE_IS_NEVER_READ!>listVar<!> = listVar + 4
+    <!ASSIGNED_VALUE_IS_NEVER_READ!>listVar<!> = <!ASSIGNMENT_TYPE_MISMATCH!>listVar + 4<!>
 }

compiler/fir/analysis-tests/testData/resolve/problems/secondaryConstructorCfg.kt

@@ -7,7 +7,7 @@ class B(p0: String) {
         p3 = p1
     }
     init {
-        p1 = p0.length
+        p1 = <!ASSIGNMENT_TYPE_MISMATCH!>p0.length<!>
         p3 = ""
     }
 }