Fix ReplaceWithOperatorAssignmentIntention in some cases

#KT-7831 Fixed

idea/testData/intentions/replaceWithOperatorAssignment/illegalMultipleOperators.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
 fun foo() {
     var x = 0
-    x = x / 1 + 1
+    x =<caret> x / 1 + 1
 }

idea/testData/intentions/replaceWithOperatorAssignment/illegalMultipleOperatorsMiddle.kt

@@ -2,5 +2,5 @@
 fun foo() {
     var x = 0
     val y = 0
-    x = y / x + 0
+    x =<caret> y / x + 0
 }

idea/testData/intentions/replaceWithOperatorAssignment/nonCommutativeRepeat.kt

@@ -0,0 +1,5 @@
+// IS_APPLICABLE: false
+fun foo() {
+    var x = 0
+    x =<caret> x - 1 - 1
+}