GH-828: Allow creating native apps with device code grant

[sergiught]

🔧 Changes

As surfaced through #828, when creating a native app with device_code grant, we're unable to create the client directly as this requires the authentication method to get set to none. It's still possible to create the client and then set the auth method to none through the auth0_client_credentials resource, however this requires 2 tf apply commands. This PR improves the DX for creating apps directly with none auth method set when device code grant is set.

📚 References

• Error when created client with device_code grant type  #828

🔬 Testing

📝 Checklist

• All new/changed/fixed functionality is covered by tests (or N/A)
• I have added documentation for all new/changed functionality (or N/A)

[codecov-commenter]

Codecov Report

Merging #833 (f86623c) into v1 (f666fdb) will decrease coverage by 0.05%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##               v1     #833      +/-   ##
==========================================
- Coverage   89.88%   89.84%   -0.05%     
==========================================
  Files          99       99              
  Lines       13685    13688       +3     
==========================================
- Hits        12301    12298       -3     
- Misses        983      987       +4     
- Partials      401      403       +2     

Files Changed	Coverage Δ
internal/auth0/client/expand.go	91.81% <100.00%> (+0.03%)	⬆️

... and 1 file with indirect coverage changes