Simplify property hierarchy in reflection

Leave only 3*2 = 6 classes: KProperty0, KProperty1, KProperty2 and their
mutable analogs, depending on the number of receivers a property takes

compiler/testData/codegen/boxWithStdlib/reflection/properties/getPropertiesMutableVsReadonly.kt

@@ -1,5 +1,5 @@
 import kotlin.reflect.jvm.kotlin
-import kotlin.reflect.KMutableMemberProperty
+import kotlin.reflect.KMutableProperty1
 
 class A(val readonly: String) {
     var mutable: String = "before"
@@ -8,12 +8,12 @@ class A(val readonly: String) {
 fun box(): String {
     val props = javaClass<A>().kotlin.properties
     val readonly = props.single { it.name == "readonly" }
-    assert(readonly !is KMutableMemberProperty<A, *>) { "Fail 1: $readonly" }
+    assert(readonly !is KMutableProperty1<A, *>) { "Fail 1: $readonly" }
     val mutable = props.single { it.name == "mutable" }
-    assert(mutable is KMutableMemberProperty<A, *>) { "Fail 2: $mutable" }
+    assert(mutable is KMutableProperty1<A, *>) { "Fail 2: $mutable" }
 
     val a = A("")
-    mutable as KMutableMemberProperty<A, String>
+    mutable as KMutableProperty1<A, String>
     assert(mutable[a] == "before") { "Fail 3: ${mutable.get(a)}" }
     mutable[a] = "OK"
     return mutable.get(a)