AbstractScriptConfigurationTest: rewrite script template setup

Allow simpler setup of common scenarios
Do not require to define DependenciesResolver for every test
Drop redundant template files

idea/testData/script/definition/highlighting/javaNestedClass/script.kts

@@ -6,4 +6,6 @@ fun f(
     <warning>i</warning>: JavaInterface.F.I
 ) {
 
-}
+}
+
+// DEPENDENCIES: classpath:lib-classes; imports:custom.library.*

idea/testData/script/definition/highlighting/javaNestedClass/template/template.kt

@@ -1,28 +0,0 @@
-package custom.scriptDefinition
-
-import kotlin.script.dependencies.*
-import kotlin.script.templates.*
-import java.io.File
-import java.util.concurrent.CompletableFuture
-import java.util.concurrent.Future
-
-class TestDependenciesResolver : ScriptDependenciesResolver {
-    override fun resolve(
-            script: ScriptContents,
-            environment: Map<String, Any?>?,
-            report: (ScriptDependenciesResolver.ReportSeverity, String, ScriptContents.Position?) -> Unit, previousDependencies: KotlinScriptExternalDependencies?
-    ): Future<KotlinScriptExternalDependencies?> {
-        return CompletableFuture.completedFuture(
-                object : KotlinScriptExternalDependencies {
-                    override val classpath: Iterable<File> = listOf(
-                            environment?.get("lib-classes") as File
-                    )
-
-                    override val imports: Iterable<String> = listOf("custom.library.*")
-                })
-
-    }
-}
-
-@ScriptTemplateDefinition(TestDependenciesResolver::class, scriptFilePattern = "script.kts")
-class Template