refactor(ui)!: re-wrote message actions and modals

[xsahil03x]

Resolves: FLU-79

Description of the pull request

This pull request combines the message actions building logic for desktop and mobile platforms by introducing a class StreamMessageAction to provide a reusable builder for message actions. Also introduced StreamMessageModal for creating message related modals in the SDK.

Screenshots / Videos

Screen.Recording.2025-05-13.at.17.11.41.mov

[codecov]

Codecov Report

Attention: Patch coverage is 63.24405% with 247 lines in your changes missing coverage. Please review.

Project coverage is 63.21%. Comparing base (4ea131e) to head (64b28d9).

Files with missing lines	Patch %	Lines
...flutter/lib/src/message_widget/message_widget.dart	31.62%	147 Missing ⚠️
...ssage_modal/message_action_confirmation_modal.dart	0.00%	22 Missing ⚠️
...t_flutter/lib/src/message_modal/message_modal.dart	54.16%	22 Missing ⚠️
...rc/fullscreen_media/full_screen_media_desktop.dart	0.00%	18 Missing ⚠️
...ib/src/message_action/message_actions_builder.dart	84.69%	15 Missing ⚠️
...t_flutter/lib/src/misc/adaptive_dialog_action.dart	63.15%	7 Missing ⚠️
.../src/message_widget/reactions/reaction_picker.dart	71.42%	6 Missing ⚠️
packages/stream_chat/lib/src/client/channel.dart	0.00%	4 Missing ⚠️
...r/lib/src/message_list_view/message_list_view.dart	50.00%	2 Missing ⚠️
...tter/lib/src/message_widget/ephemeral_message.dart	0.00%	2 Missing ⚠️
... and 1 more

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2156      +/-   ##
==========================================
+ Coverage   63.16%   63.21%   +0.04%     
==========================================
  Files         402      397       -5     
  Lines       25229    25065     -164     
==========================================
- Hits        15937    15845      -92     
+ Misses       9292     9220      -72     

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[Copilot]

Pull Request Overview

This pull request refactors the message actions and modal system to consolidate duplicated UI components and improve type safety. Key changes include:

• Removal of individual action button widgets in favor of a generic, reusable builder (StreamMessageActionsBuilder) and modal (StreamMessageModal).
• Updates to the retry logic in channel operations and localization tweaks for consistency.
• Various cleanups and removals of legacy context menu and action files to streamline the codebase.

Reviewed Changes

Copilot reviewed 101 out of 101 changed files in this pull request.

Show a summary per file

File	Description
packages/stream_chat_flutter/lib/src/message_actions_modal/*	Removed legacy message action button widgets in favor of a centralized approach.
packages/stream_chat_flutter/lib/src/message_action/message_actions_builder.dart	Introduced a new builder class to generate message actions based on state and channel capabilities.
packages/stream_chat_flutter/lib/src/message_action/*	Added new generic message action types and updated related widgets for improved type safety.
packages/stream_chat_flutter/lib/src/fullscreen_media/full_screen_media_desktop.dart	Updated DownloadMenuItem integration and adjusted menu builder for desktop media.
packages/stream_chat_flutter/lib/src/localization/translations.dart	Revised error messages to remove line breaks and standardize wording.
packages/stream_chat_flutter/lib/src/channel/channel.dart	Updated retryMessage logic with enhanced assertions and clearer retry paths.
packages/stream_chat_flutter/CHANGELOG.md, dart_test.yaml	Updated changelog and test configuration to reflect the refactor.