UX: Improve seeded LLM edit page

[keegangeorge]

🔎 Overview

This PR makes various small improvements to the LLM editor form for seeded LLMs.

Specifically we:

• disable name, id, and provider inputs from being changed (altering these doesn't persist anyway, we only want to show it to the user as information)
• show AI bot user info for LLM as it could be useful for user despite being a seeded LLM
• consistently use i18n template helper in the template
• use @label property of <DButton /> instead of making it a wrapper component and placing the translated label inside it
• fix incorrect data attribute naming [data-persona-id] should be [data-llm-id]
• add lacking system specs

📸 Screenshots

Before:

After: