Refactor host configuration handling and script definition creation

so it is possible now to create custom host configuration with template
and all configurations are handled consistenly.
Also introduce and use new ScriptDefinition class wrapping compilation
and evaluation configurations, that could be consistenly created from a
template.

libraries/scripting/jvm/src/kotlin/script/experimental/jvm/runner.kt

@@ -11,25 +11,24 @@ import kotlin.coroutines.EmptyCoroutineContext
 import kotlin.coroutines.startCoroutine
 import kotlin.script.experimental.api.*
 import kotlin.script.experimental.host.createEvaluationConfigurationFromTemplate
+import kotlin.script.experimental.host.withDefaultsFrom
 import kotlin.script.experimental.jvm.impl.createScriptFromClassLoader
 
 @Suppress("unused") // script codegen generates a call to it
 fun runCompiledScript(scriptClass: Class<*>, vararg args: String) {
     val script = createScriptFromClassLoader(scriptClass.name, scriptClass.classLoader)
     val evaluator = BasicJvmScriptEvaluator()
-    val hostConfiguration = script.compilationConfiguration[ScriptCompilationConfiguration.hostConfiguration]
-        ?: defaultJvmScriptingHostConfiguration
-    val baseEvaluationConfiguration =
+    val evaluationConfiguration =
         createEvaluationConfigurationFromTemplate(
             script.compilationConfiguration[ScriptCompilationConfiguration.baseClass]!!,
-            hostConfiguration,
+            script.compilationConfiguration[ScriptCompilationConfiguration.hostConfiguration]
+                .withDefaultsFrom(defaultJvmScriptingHostConfiguration),
             scriptClass.kotlin
-        )
-    val evaluationConfiguration = ScriptEvaluationConfiguration(baseEvaluationConfiguration) {
-        jvm {
-            mainArguments(args)
+        ) {
+            jvm {
+                mainArguments(args)
+            }
         }
-    }
     runScriptSuspend {
         evaluator(script, evaluationConfiguration).onFailure {
             it.reports.forEach(System.err::println)