GH-863: Fix how we fetch organizations by name in data source

[sergiught]

🔧 Changes

This PR fixes the logic on fetching organizations by name by leveraging the dedicated endpoint https://auth0.com/docs/api/management/v2/organizations/get-name-by-name instead of using offset pagination and looping through the results. This fixes #863

📚 References

• Plan and apply failing due to records limit #863

🔬 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 #877 (8771b4f) into main (0a39d61) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #877   +/-   ##
=======================================
  Coverage   89.97%   89.97%           
=======================================
  Files         101      101           
  Lines       13799    13782   -17     
=======================================
- Hits        12415    12401   -14     
+ Misses        983      980    -3     
  Partials      401      401           

Files	Coverage Δ
internal/auth0/organization/data_source.go	87.03% <100.00%> (+5.43%)	⬆️

... and 1 file with indirect coverage changes