Brief Title

Feat: Message & Chat Input UI Enhancement for Edit Message Functionality

Acceptance Criteria fulfillment

• When a message is clicked to be edited, its background color changes dynamically to indicate it is being edited.
• The background color of the chat input box matches the edited message's background color.
• The implementation dynamically handles light and dark themes, ensuring appropriate color contrast for both.
• Ensure smooth transition between color changes for both message and chat input box.

Fixes #897

Video/Screenshots

and

PR Test Details

Note: The PR will be ready for live testing at https://rocketchat.github.io/EmbeddedChat/pulls/pr-898 after approval. Contributors are requested to replace <pr_number> with the actual PR number.