Show error if doctor is not linked to the consultation facility

[shivankacker]

Proposed Changes

• Adds an error message if the doctor is not associated to the facility anymore

Associated Issue

• Fixes Improve the Error for Consultation Form care_fe#8142

Merge Checklist

• Tests added/fixed
• Update docs in /docs
• Linting Complete
• Any other necessary step

Only PR's with test cases included and passing lint and test pipelines will be reviewed

@coronasafe/care-backend-maintainers @coronasafe/care-backend-admins

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 63.73%. Comparing base (ac7f696) to head (e32d015).
Report is 1 commits behind head on develop.

Files	Patch %	Lines
...e/facility/api/serializers/patient_consultation.py	0.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2309      +/-   ##
===========================================
+ Coverage    63.70%   63.73%   +0.02%     
===========================================
  Files          238      238              
  Lines        13316    13342      +26     
  Branches      1897     1904       +7     
===========================================
+ Hits          8483     8503      +20     
- Misses        4481     4486       +5     
- Partials       352      353       +1     

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