Updated the error message for invalid odk-credentials

[Sujanadh]

What type of PR is this? (check all applicable)

• 🍕 Feature
• 🐛 Bug Fix
• 📝 Documentation Update
• 🎨 Style
• 🧑‍💻 Code Refactor
• 🔥 Performance Improvements
• ✅ Test
• 🤖 Build
• 🔁 CI
• 📦 Chore (Release)
• ⏩ Revert

Describe this PR

This PR checks for ODK credential authentication and returns a custom error message for invalid ODK credentials.

Response

{
  "detail": "Error creating project on ODK Central: ODK credentials are invalid, or may have been updated. Please update them."
}

Checklist before requesting a review

• 📖 Read the FMTM Contributing Guide: https://github.com/hotosm/fmtm/blob/main/CONTRIBUTING.md
• 📖 Read the FMTM Code of Conduct: https://github.com/hotosm/fmtm/blob/main/CODE_OF_CONDUCT.md
• 👷‍♀️ Create small PRs. In most cases, this will be possible.
• ✅ Provide tests for your changes.
• 📝 Use descriptive commit messages.
• 📗 Update any related documentation and include any relevant screenshots.

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