DEVX-299 : Manage OAuth clients (incl. secrets)

[vaibhavatlan]

✨ Description

Adds comprehensive OAuth client management capabilities to the Python SDK :

• OAuth Client Creation - New create() method for programmatically creating OAuth clients with name, role, description, and persona_qns parameters
• Simplified Role Resolution - Role parameter accepts human-readable descriptions (e.g., "Admin", "Member") and auto-resolves to API values
• Full CRUD Support - Create, retrieve, update, and delete OAuth clients
• Sync & Async - Support for both synchronous and asynchronous clients

Linear link: https://linear.app/atlan-epd/issue/DEVX-299/manage-oauth-clients-incl-secrets

---

🧩 Type of change

Select all that apply:

• 🚀 New feature (non-breaking change that adds functionality)
• 🐛 Bug fix (non-breaking change that fixes an issue) — please include tests! Refer testing-toolkit 🧪
• 🔄 Refactor (code change that neither fixes a bug nor adds a feature)
• 🧹 Maintenance (chores, cleanup, minor improvements)
• 💥 Breaking change (fix or feature that may break existing functionality)
• 📦 Dependency upgrade/downgrade
• 📚 Documentation updates

---

✅ How has this been tested? (e.g. screenshots, logs, workflow links)

Describe how the change was tested. Include:

• Steps to reproduce
• Any relevant screenshots, logs, or links to successful workflow runs
• Details on environment/setup if applicable

---

📋 Checklist

• My code follows the project’s style guidelines
• I’ve performed a self-review of my code
• I’ve added comments in tricky or complex areas
• I’ve updated the documentation as needed
• There are no new warnings from my changes
• I’ve added tests to cover my changes
• All new and existing tests pass locally

[Aryamanz29]

Good progress 💯 - see my comments below:

[Aryamanz29]

Looks good - minor test improvements:

[Aryamanz29]

LGTM - thanks! 🚀