FIR: add class type parameters to constructors & change their rendering

compiler/fir/resolve/testData/loadCompiledKotlin/enum/InnerEnum.txt

@@ -1,8 +1,8 @@
 public final class A : R|kotlin/Any| {
-    public constructor()
+    public constructor(): R|test/A|
 
     public final enum class E : R|kotlin/Enum<test/A.E>| {
-        private constructor()
+        private constructor(): R|test/A.E|
 
     }