Multiple templates with concatenation generator should add spaces after commas (KT-27954)

idea/testData/codeInsight/generate/toString/multipeTemplates/arrays.kt.after

@@ -10,8 +10,8 @@ class A(val n: IntArray, val s: Array<String>) {
 
     override fun toString(): String {
         return "A(" +
-                "n=${Arrays.toString(n)}," +
-                "s=${Arrays.toString(s)}," +
+                "n=${Arrays.toString(n)}, " +
+                "s=${Arrays.toString(s)}, " +
                 "f=$f" +
                 ")"
     }

idea/testData/codeInsight/generate/toString/multipeTemplates/customAccessors.kt.after

@@ -7,7 +7,7 @@ class Test {
     var name: String = ""
     <caret>override fun toString(): String {
         return "Test(" +
-                "serial='$serial'," +
+                "serial='$serial', " +
                 "name='$name'" +
                 ")"
     }

idea/testData/codeInsight/generate/toString/multipeTemplates/dataClass.kt.after

@@ -2,7 +2,7 @@
 data class A(val n: Int, val s: String?) {
     override fun toString(): String {
         return "A(" +
-                "n=$n," +
+                "n=$n, " +
                 "s=$s" +
                 ")"
     }

idea/testData/codeInsight/generate/toString/multipeTemplates/keepQuotes.kt.after

@@ -2,8 +2,8 @@
 class Example(val `in`: String, val `cl ass`: String, val `valid`: Boolean) {
     override fun toString(): String {
         return "Example(" +
-                "`in`='$`in`'," +
-                "`cl ass`='$`cl ass`'," +
+                "`in`='$`in`', " +
+                "`cl ass`='$`cl ass`', " +
                 "`valid`=$`valid`" +
                 ")"
     }

idea/testData/codeInsight/generate/toString/multipeTemplates/multipleVars.kt.after

@@ -8,8 +8,8 @@ class A(val n: Int, val s: String) {
 
     override fun toString(): String {
         return "A(" +
-                "n=$n," +
-                "s='$s'," +
+                "n=$n, " +
+                "s='$s', " +
                 "f=$f" +
                 ")"
     }

idea/testData/codeInsight/generate/toString/multipeTemplates/multipleVarsWithSuperClass.kt.after

@@ -13,8 +13,8 @@ class A(val n: Int, val s: String) : X() {
 
     override fun toString(): String {
         return "A(" +
-                "n=$n," +
-                "s='$s'," +
+                "n=$n, " +
+                "s='$s', " +
                 "f=$f" +
                 ")" +
                 " ${super.toString()}"