Mgmtdomains API, better validation and messages

[indy-independence]

Improve input validating for mgmtdomains using pydantic. Add output after updating a mgmtdomain object. Better error messages for updating/adding mgmtdomains

[codecov]

Codecov Report

Merging #177 (5d04574) into develop (8df1862) will increase coverage by 0.59%.
The diff coverage is 66.66%.

@@             Coverage Diff             @@
##           develop     #177      +/-   ##
===========================================
+ Coverage    58.28%   58.87%   +0.59%     
===========================================
  Files           60       60              
  Lines         6002     6040      +38     
===========================================
+ Hits          3498     3556      +58     
+ Misses        2504     2484      -20     

Impacted Files	Coverage Δ
src/cnaas_nms/api/mgmtdomain.py	46.15% <56.00%> (+21.34%)	⬆️
src/cnaas_nms/api/generic.py	58.77% <85.18%> (+8.19%)	⬆️
src/cnaas_nms/db/settings_fields.py	94.50% <100.00%> (+0.03%)	⬆️
src/cnaas_nms/db/settings.py	81.69% <0.00%> (+0.26%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 8df1862...5d04574. Read the comment docs.