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/shared/Stubs/ScriptFactoryStub.ts

@@ -1,13 +1,13 @@
-import type { ScriptFactory } from '@/application/Parser/Script/ScriptParser';
-import type { IScript } from '@/domain/IScript';
-import type { ScriptInitParameters } from '@/domain/Script';
+import type { ScriptFactory } from '@/application/Parser/Executable/Script/ScriptParser';
+import type { Script } from '@/domain/Executables/Script/Script';
+import type { ScriptInitParameters } from '@/domain/Executables/Script/CollectionScript';
 import { ScriptStub } from './ScriptStub';
 
 export function createScriptFactorySpy(): {
   readonly scriptFactorySpy: ScriptFactory;
-  getInitParameters: (category: IScript) => ScriptInitParameters | undefined;
+  getInitParameters: (category: Script) => ScriptInitParameters | undefined;
 } {
-  const createdScripts = new Map<IScript, ScriptInitParameters>();
+  const createdScripts = new Map<Script, ScriptInitParameters>();
   return {
     scriptFactorySpy: (parameters) => {
       const script = new ScriptStub('script from factory stub');