APP-8170 Add optional parameters to AtlanClient.from_token_guid method

[ErnestoLoma]

✨ Description

Modify the AtlanClient.from_token_guid method to include optional parameters for base_url, client_id, and client_secret. These parameters should fall back to the configured environment variables if not provided.

Jira link: APP-8170

---

🧩 Type of change

Select all that apply:

• [ X] 🚀 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]

LGTM 🚀