Fix double quotes in diagnostic messages

For diagnostics without any parameters, the given text is simply rendered as a
String, so no symbols should be escaped.

For diagnostics with parameters, the format in java.text.MessageFormat is used,
so one single quote is erased and two single quotes become one single quote in
the rendered text.

idea/testData/intentions/conventionNameCalls/replaceCallWithUnaryOperator/functionLiteralArgument.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-// ERROR: operator modifier is inapplicable on this function: must have no value parameters
+// ERROR: 'operator' modifier is inapplicable on this function: must have no value parameters
 fun test() {
     class Test {
         operator fun unaryPlus(fn: () -> Unit): Test = Test()

idea/testData/intentions/conventionNameCalls/replaceCallWithUnaryOperator/namedValueArgument.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-// ERROR: operator modifier is inapplicable on this function: must have no value parameters
+// ERROR: 'operator' modifier is inapplicable on this function: must have no value parameters
 fun test() {
     class Test {
         operator fun unaryPlus(a: Int): Test = Test()

idea/testData/intentions/conventionNameCalls/replaceCallWithUnaryOperator/unacceptableVararg.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-// ERROR: operator modifier is inapplicable on this function: must have no value parameters
+// ERROR: 'operator' modifier is inapplicable on this function: must have no value parameters
 fun test() {
     class Test {
         operator fun unaryPlus(vararg a: Int): Test = Test()

idea/testData/intentions/conventionNameCalls/replaceCallWithUnaryOperator/valueArgument.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-// ERROR: operator modifier is inapplicable on this function: must have no value parameters
+// ERROR: 'operator' modifier is inapplicable on this function: must have no value parameters
 fun test() {
     class Test {
         operator fun unaryPlus(a: Int): Test = Test()