Change parsing rules for primary constructor

- Parse 'constructor' keyword before value arguments
- Allow unescaped annotations

compiler/testData/psi/primaryConstructor/recovery.kt

@@ -0,0 +1,18 @@
+class A0 @Ann (x: Int) {
+    val x = 1
+}
+
+class A1 Ann : Base()
+
+class A2 Ann
+
+class A3 Ann {
+    fun foo()
+}
+
+class A4 constructor {}
+class A5 constructor : Base {}
+
+class A7 Ann(1) (x: Int)
+class A8 Ann() {}
+class A9 Ann() : Base()