Use outermost test class for test class util method provider and renderer context

Author: ArsenHD

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/model/constructor/context/CgContext.kt

@@ -476,7 +476,7 @@ internal data class CgContext(
         get() = if (generateUtilClassFile) {
             UtilClassFileMethodProvider
         } else {
-            TestClassUtilMethodProvider(currentTestClass)
+            TestClassUtilMethodProvider(outerMostTestClass)
         }
 
     override lateinit var currentTestClass: ClassId

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/model/visitor/CgRendererContext.kt

@@ -33,7 +33,7 @@ internal class CgRendererContext(
                 importedClasses = context.importedClasses,
                 importedStaticMethods = context.importedStaticMethods,
                 classPackageName = context.testClassPackageName,
-                generatedClass = context.currentTestClass,
+                generatedClass = context.outerMostTestClass,
                 utilMethodProvider = context.utilMethodProvider,
                 codegenLanguage = context.codegenLanguage,
                 mockFrameworkUsed = context.mockFrameworkUsed,