Rename workspace agent to architect

[JonasHelming]

fixed #14962

What it does

• rename workspace agent to 'Architect'
• Refine and focus Architect prompt
• Refine the description of Coder and Architect to make the difference clear

How to test

• Talk to Architect
• Test Orchestration between Coder and Architect

Known issue: Sometimes it uses Universal where it could use Workspace, as most LLMs have generic knowledge about Theia. You can add something like 'in my project' to circumvent this.

Follow-ups

Breaking changes

• This PR introduces breaking changes and requires careful review. If yes, the breaking changes section in the changelog has been updated.

Attribution

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[planger]

Works nicely, also in combination with the Coder and the Orchestrator. Thank you!