[cards]: additional actions

[lilyydu]

closes: #57

adds in the remaining actions for cards package, matching C#

[Copilot]

Pull Request Overview

This PR adds five additional action classes to the cards package to match the C# implementation, providing a complete set of Teams card actions for Python developers.

• Implements TaskFetchAction, SignInAction, MessageBackAction, InvokeAction, and IMBackAction classes
• Adds comprehensive test coverage for all new action types
• Updates package exports to include the new actions

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/cards/src/microsoft/teams/cards/actions/task_fetch_action.py	Implements TaskFetchAction for task module fetching operations
packages/cards/src/microsoft/teams/cards/actions/sign_in_action.py	Implements SignInAction for authentication workflows
packages/cards/src/microsoft/teams/cards/actions/message_back_action.py	Implements MessageBackAction for message responses with optional display text
packages/cards/src/microsoft/teams/cards/actions/invoke_action.py	Implements InvokeAction for bot invoke operations
packages/cards/src/microsoft/teams/cards/actions/im_back_action.py	Implements IMBackAction for instant message responses
packages/cards/src/microsoft/teams/cards/actions/init.py	Exports all new action classes
packages/cards/src/microsoft/teams/cards/init.py	Updates main package exports to include actions
packages/cards/tests/test_*.py	Comprehensive test coverage for all new action classes

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}