[JS IR] webpackConfigAppliers as internal to not break Gradle lambda serialization in some cases

[JS IR] Add synthetic config and webpack config is nested object

^KT-43535 fixed

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinBrowserJsIr.kt

@@ -45,10 +45,10 @@ open class KotlinBrowserJsIr @Inject constructor(target: KotlinJsIrTarget) :
 
     override fun commonWebpackConfig(body: KotlinWebpackConfig.() -> Unit) {
         webpackTaskConfigurations.add {
-            webpackConfigAppliers.add(body)
+            webpackConfigApplier(body)
         }
         runTaskConfigurations.add {
-            webpackConfigAppliers.add(body)
+            webpackConfigApplier(body)
         }
         testTask {
             onTestFrameworkSet {

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/subtargets/KotlinBrowserJs.kt

@@ -51,10 +51,10 @@ open class KotlinBrowserJs @Inject constructor(target: KotlinJsTarget) :
 
     override fun commonWebpackConfig(body: KotlinWebpackConfig.() -> Unit) {
         webpackTaskConfigurations.add {
-            webpackConfigAppliers.add(body)
+            webpackConfigApplier(body)
         }
         runTaskConfigurations.add {
-            webpackConfigAppliers.add(body)
+            webpackConfigApplier(body)
         }
         testTask {
             onTestFrameworkSet {

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/webpack/KotlinWebpack.kt

@@ -185,8 +185,15 @@ constructor(
     @Internal
     var generateConfigOnly: Boolean = false
 
-    @Input
-    val webpackConfigAppliers: MutableList<(KotlinWebpackConfig) -> Unit> =
+    @Nested
+    val synthConfig = KotlinWebpackConfig()
+
+    fun webpackConfigApplier(body: KotlinWebpackConfig.() -> Unit) {
+        synthConfig.body()
+        webpackConfigAppliers.add(body)
+    }
+
+    private val webpackConfigAppliers: MutableList<(KotlinWebpackConfig) -> Unit> =
         mutableListOf()
 
     private fun createRunner(): KotlinWebpackRunner {

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/webpack/KotlinWebpackConfig.kt

@@ -8,6 +8,10 @@
 package org.jetbrains.kotlin.gradle.targets.js.webpack
 
 import com.google.gson.GsonBuilder
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.Internal
+import org.gradle.api.tasks.Nested
+import org.gradle.api.tasks.Optional
 import org.jetbrains.kotlin.gradle.targets.js.NpmVersions
 import org.jetbrains.kotlin.gradle.targets.js.RequiredKotlinJsDependency
 import org.jetbrains.kotlin.gradle.targets.js.appendConfigsFromDir
@@ -21,24 +25,71 @@ import java.io.StringWriter
 
 @Suppress("MemberVisibilityCanBePrivate")
 data class KotlinWebpackConfig(
+    @Input
     var mode: Mode = Mode.DEVELOPMENT,
+    @Internal
     var entry: File? = null,
+    @Nested
+    @Optional
     var output: KotlinWebpackOutput? = null,
+    @Internal
     var outputPath: File? = null,
+    @Input
+    @Optional
     var outputFileName: String? = entry?.name,
+    @Internal
     var configDirectory: File? = null,
+    @Internal
     var bundleAnalyzerReportDir: File? = null,
+    @Internal
     var reportEvaluatedConfigFile: File? = null,
+    @Input
+    @Optional
     var devServer: DevServer? = null,
+    @Nested
     var cssSupport: KotlinWebpackCssSupport = KotlinWebpackCssSupport(),
+    @Input
+    @Optional
     var devtool: String? = WebpackDevtool.EVAL_SOURCE_MAP,
+    @Input
     var showProgress: Boolean = false,
+    @Input
     var sourceMaps: Boolean = false,
+    @Input
     var export: Boolean = true,
+    @Input
     var progressReporter: Boolean = false,
+    @Input
+    @Optional
     var progressReporterPathFilter: String? = null,
+    @Input
     var resolveFromModulesFirst: Boolean = false
 ) {
+    @get:Input
+    @get:Optional
+    val entryInput: String?
+        get() = entry?.absoluteFile?.normalize()?.absolutePath
+
+    @get:Input
+    @get:Optional
+    val outputPathInput: String?
+        get() = outputPath?.absoluteFile?.normalize()?.absolutePath
+
+    @get:Input
+    @get:Optional
+    val configDirectoryInput: String?
+        get() = configDirectory?.absoluteFile?.normalize()?.absolutePath
+
+    @get:Input
+    @get:Optional
+    val bundleAnalyzerReportDirInput: String?
+        get() = bundleAnalyzerReportDir?.absoluteFile?.normalize()?.absolutePath
+
+    @get:Input
+    @get:Optional
+    val reportEvaluatedConfigFileInput: String?
+        get() = reportEvaluatedConfigFile?.absoluteFile?.normalize()?.absolutePath
+
     fun getRequiredDependencies(versions: NpmVersions) =
         mutableSetOf<RequiredKotlinJsDependency>().also {
             it.add(versions.kotlinJsTestRunner)