Add convenient extension methods to get variant implementation factory

^KT-47047 In Progress

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinPlugin.kt

@@ -413,8 +413,8 @@ internal abstract class AbstractKotlinPlugin(
             }
         }
 
-        VariantImplementationFactories
-            .get(project.gradle)[MavenPluginConfigurator.MavenPluginConfiguratorVariantFactory::class]
+        project.gradle
+            .variantImplementationFactory<MavenPluginConfigurator.MavenPluginConfiguratorVariantFactory>()
             .getInstance()
             .applyConfiguration(project, target, shouldRewritePoms)
     }

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/VariantImplementationFactories.kt

@@ -56,4 +56,12 @@ abstract class VariantImplementationFactories : BuildService<BuildServiceParamet
 
         fun get(gradle: Gradle): VariantImplementationFactories = getProvider(gradle).get()
     }
-}
+}
+
+internal inline fun <reified T : VariantImplementationFactories.VariantImplementationFactory> Gradle.variantImplementationFactory(): T =
+    VariantImplementationFactories.get(this)[T::class]
+
+internal inline fun <
+        reified T : VariantImplementationFactories.VariantImplementationFactory
+        > Gradle.variantImplementationFactoryProvider(): Provider<T> =
+    VariantImplementationFactories.getProvider(this).map { it[T::class] }