Refactor to unify scripts/categories as Executable

This commit consolidates scripts and categories under a unified
'Executable' concept. This simplifies the architecture and improves code
readability.

- Introduce subfolders within `src/domain` to segregate domain elements.
- Update class and interface names by removing the 'I' prefix in
  alignment with new coding standards.
- Replace 'Node' with 'Executable' to clarify usage; reserve 'Node'
  exclusively for the UI's tree component.

tests/unit/application/Parser/Executable/Validation/DataValidationTestScenarioGenerator.ts

@@ -0,0 +1,36 @@
+export interface DataValidationTestScenario<T> {
+  readonly description: string;
+  readonly data: T;
+  readonly expectedPass: boolean;
+  readonly expectedMessage?: string;
+}
+
+export function generateDataValidationTestScenarios<T>(
+  ...conditionBasedScenarios: DataValidationConditionBasedTestScenario<T>[]
+): DataValidationTestScenario<T>[] {
+  return conditionBasedScenarios.flatMap((conditionScenario) => [
+    conditionScenario.expectFail.map((failDefinition): DataValidationTestScenario<T> => ({
+      description: `fails: "${failDefinition.description}"`,
+      data: failDefinition.data,
+      expectedPass: false,
+      expectedMessage: conditionScenario.assertErrorMessage,
+    })),
+    conditionScenario.expectPass.map((passDefinition): DataValidationTestScenario<T> => ({
+      description: `passes: "${passDefinition.description}"`,
+      data: passDefinition.data,
+      expectedPass: true,
+      expectedMessage: conditionScenario.assertErrorMessage,
+    })),
+  ].flat());
+}
+
+interface DataValidationConditionBasedTestScenario<T> {
+  readonly assertErrorMessage?: string;
+  readonly expectPass: readonly DataValidationScenarioDefinition<T>[];
+  readonly expectFail: readonly DataValidationScenarioDefinition<T>[];
+}
+
+interface DataValidationScenarioDefinition<T> {
+  readonly description: string;
+  readonly data: T;
+}