Fix code highlighting and optimize category select

This commit introduces a batched debounce mechanism for managing user
selection state changes. It effectively reduces unnecessary processing
during rapid script checking, preventing multiple triggers for code
compilation and UI rendering.

Key improvements include:

- Enhanced performance, especially noticeable when selecting large
  categories. This update resolves minor UI freezes experienced when
  selecting categories with numerous scripts.
- Correction of a bug where the code area only highlighted the last
  selected script when multiple scripts were chosen.

Other changes include:

- Timing functions:
  - Create a `Timing` folder for `throttle` and the new
    `batchedDebounce` functions.
  - Move these functions to the application layer from the presentation
    layer, reflecting their application-wide use.
  - Refactor existing code for improved clarity, naming consistency, and
    adherence to new naming conventions.
  - Add missing unit tests.
- `UserSelection`:
  - State modifications in `UserSelection` now utilize a singular object
    inspired by the CQRS pattern, enabling batch updates and flexible
    change configurations, thereby simplifying change management.
- Remove the `I` prefix from related interfaces to align with new coding
  standards.
- Refactor related code for better testability in isolation with
  dependency injection.
- Repository:
  - Move repository abstractions to the application layer.
  - Improve repository abstraction to combine `ReadonlyRepository` and
    `MutableRepository` interfaces.
- E2E testing:
  - Introduce E2E tests to validate the correct batch selection
    behavior.
  - Add a specialized data attribute in `TheCodeArea.vue` for improved
    testability.
  - Reorganize shared Cypress functions for a more idiomatic Cypress
    approach.
  - Improve test documentation with related information.
- `SelectedScript`:
  - Create an abstraction for simplified testability.
  - Introduce `SelectedScriptStub` in tests as a substitute for the
    actual object.

tests/unit/shared/Stubs/CategorySelectionStub.ts

@@ -0,0 +1,33 @@
+import { CategorySelection } from '@/application/Context/State/Selection/Category/CategorySelection';
+import { CategorySelectionChangeCommand } from '@/application/Context/State/Selection/Category/CategorySelectionChange';
+import { StubWithObservableMethodCalls } from './StubWithObservableMethodCalls';
+
+export class CategorySelectionStub
+  extends StubWithObservableMethodCalls<CategorySelection>
+  implements CategorySelection {
+  public isCategorySelected(categoryId: number, revert: boolean): boolean {
+    const call = this.callHistory.find(
+      (c) => c.methodName === 'processChanges'
+      && c.args[0].changes.some((change) => (
+        change.newStatus.isSelected === true
+        && change.newStatus.isReverted === revert
+        && change.categoryId === categoryId)),
+    );
+    return call !== undefined;
+  }
+
+  public areAllScriptsSelected(): boolean {
+    throw new Error('Method not implemented.');
+  }
+
+  public isAnyScriptSelected(): boolean {
+    throw new Error('Method not implemented.');
+  }
+
+  public processChanges(action: CategorySelectionChangeCommand): void {
+    this.registerMethodCall({
+      methodName: 'processChanges',
+      args: [action],
+    });
+  }
+}