fix(richtext-lexical): prevent TS CodeBlocks from sharing Monaco model (useId)

[technicaldirector]

Changes

• Used React’s built-in useId() to give each TypeScript CodeBlock instance a unique Monaco defaultPath. This ensures every TS code block creates its own Monaco model instead of reusing a single shared model.
• Exported the Horizontal Rule node from the client exports so it’s available to consumers.

Why I did it

Issue + Video mentioned here
According to the @monaco-editor/react documentation, the path/defaultPath parameter is used as an identifier for the model:

There are three parameters to create a model - value, language and path (monaco.editor.createModel(value, language, monaco.Uri.parse(path))). You can consider last one (path) as an identifier for the model. The Editor component, now, has a path prop. When you specify a path prop, the Editor component checks if it has a model by that path or not. If yes, the existing model will be shown, otherwise, a new one will be created (and stored).

When multiple code blocks share the same defaultPath: 'file.tsx', @monaco-editor/react treats them as the same model identifier, causing:

• Model reuse across different code block instances
• Content synchronization between blocks
• Loss of independent state per block

[AlessioGr]

Thank you!

[github-actions]

🚀 This is included in version v3.62.0