Add Copy Button and Language Name to Code Blocks in Code Highlighter Plugin

[itw-DheerG]

Currently, code blocks rendered by the Code Highlighter plugin do not display the language name or provide a convenient way to copy the code. To improve user experience, enhance all code blocks by:

• Wrapping each block in a container.
• Displaying the detected language name (from the code class, e.g., language-plaintext).
• Adding a "Copy" button that copies the code to the clipboard.
• Ensuring the enhancement works on all pages, regardless of how code blocks are rendered.
• Applying minimal, modern styling for the header and button.