feat: improving Task API

[tnaum-ms]

This pull request introduces new task-related features and updates localization strings to support task management and progress tracking. The most significant changes include the addition of a DemoTask class to demonstrate task handling and progress updates, and new localized strings for task states and operations.

Task Management Enhancements:

• src/services/tasks/DemoTask.ts: Added a DemoTask class that simulates a task with progress updates and optional failure for testing purposes. It includes initialization, cleanup, and error handling logic.
• src/services/tasks/index.ts: Exported the DemoTask class to make it accessible for use in other parts of the application.

Localization Updates:

• l10n/bundle.l10n.json: Added several new localized strings related to task states and operations, including messages for task initialization, progress tracking, completion, failure, and stopping. [1] [2] [3] [4] [5] [6]

[Copilot]

Pull Request Overview

This PR enhances task management by introducing a simulated DemoTask, exporting it for wider use, and adding localized messages to support task lifecycle states.

• Introduce DemoTask class with progress updates, optional failure simulation, and cleanup logic
• Export DemoTask in the tasks index for external consumption
• Add new localization keys for task initialization, progress, completion, failure, and stopping
• Update contributor guidelines regarding test file placement

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

File	Description
src/services/tasks/DemoTask.ts	Implements DemoTask class that simulates work, reports progress, and optionally fails
src/services/taskService.test.ts	Adds comprehensive unit tests for TaskService and task state flows
l10n/bundle.l10n.json	Adds localized strings for task states and operations
.github/copilot-instructions.md	Revises testing guideline for test file placement

Comments suppressed due to low confidence (2)

src/services/tasks/DemoTask.ts:16

• Newly introduced DemoTask lacks dedicated unit tests. Consider adding tests to verify its progress reporting, cleanup behavior, and failure simulation.

export class DemoTask extends Task {

.github/copilot-instructions.md:239

• [nitpick] This update may conflict with the repository's convention of placing tests under the test/ folder mirroring source structure. Clarify whether tests should be co-located with code or in a separate test/ directory.

- Keep tests in the same directory as the code they test.