[FIR/IR generator] Inherit TypeRef from Importable

This is the first step to replace the usages of `Importable`
in the FIR generator with `TypeRef`.

This is a step towards commonizing the code generator between
FIR and IR: KT-61970

compiler/ir/ir.tree/tree-generator/src/org/jetbrains/kotlin/ir/generator/config/ConfigModel.kt

@@ -10,6 +10,7 @@ import com.squareup.kotlinpoet.PropertySpec
 import com.squareup.kotlinpoet.TypeSpec
 import org.jetbrains.kotlin.generators.tree.*
 import org.jetbrains.kotlin.ir.generator.BASE_PACKAGE
+import org.jetbrains.kotlin.ir.generator.model.Element
 import org.jetbrains.kotlin.ir.generator.util.*
 
 class Config(
@@ -71,6 +72,14 @@ class ElementConfig(
 
     override fun toString() = element.name
 
+    override val packageName: String
+        get() = category.packageName
+
+    override val type: String
+        get() = Element.elementName2typeName(name)
+
+    override fun getTypeWithArguments(notNull: Boolean): String = type
+
     enum class Category(private val packageDir: String, val defaultVisitorParam: String) {
         Expression("expressions", "expression"),
         Declaration("declarations", "declaration"),
@@ -93,6 +102,14 @@ class ElementConfigRef(
     override fun copy(nullable: Boolean) = ElementConfigRef(element, args, nullable)
 
     override fun toString() = element.name
+
+    override val type: String
+        get() = element.type
+
+    override val packageName: String
+        get() = element.packageName
+
+    override fun getTypeWithArguments(notNull: Boolean): String = type + generics
 }
 
 sealed class UseFieldAsParameterInIrFactoryStrategy {

compiler/ir/ir.tree/tree-generator/src/org/jetbrains/kotlin/ir/generator/model/Model.kt

@@ -87,6 +87,14 @@ data class ElementRef(
     override fun copy(args: Map<NamedTypeParameterRef, TypeRef>) = ElementRef(element, args, nullable)
     override fun copy(nullable: Boolean) = ElementRef(element, args, nullable)
     override fun toString() = "${element.name}<${args}>"
+
+    override val type: String
+        get() = element.typeName
+
+    override val packageName: String
+        get() = element.packageName
+
+    override fun getTypeWithArguments(notNull: Boolean): String = type + generics
 }
 
 sealed class Field(

compiler/ir/ir.tree/tree-generator/src/org/jetbrains/kotlin/ir/generator/model/Transformations.kt

@@ -12,7 +12,16 @@ import org.jetbrains.kotlin.utils.addToStdlib.UnsafeCastFunction
 import org.jetbrains.kotlin.utils.addToStdlib.castAll
 import org.jetbrains.kotlin.utils.addToStdlib.partitionIsInstance
 
-private object InferredOverriddenType : TypeRef
+private object InferredOverriddenType : TypeRef {
+    override val type: String
+        get() = error("not supported")
+    override val packageName: String?
+        get() = null
+
+    override fun getTypeWithArguments(notNull: Boolean): String {
+        error("not supported")
+    }
+}
 
 data class Model(val elements: List<Element>, val rootElement: Element)