[bug] Enforce at least one beacon id provided to create quest

[KCarretto]

Fixes #727

[codecov]

Codecov Report

Attention: Patch coverage is 25.00000% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 69.22%. Comparing base (e216d53) to head (c6d70b5).

Files	Patch %	Lines
tavern/internal/graphql/mutation.resolvers.go	25.00%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #729      +/-   ##
==========================================
+ Coverage   66.27%   69.22%   +2.95%     
==========================================
  Files         179      179              
  Lines       12193    12735     +542     
==========================================
+ Hits         8081     8816     +735     
+ Misses       3885     3691     -194     
- Partials      227      228       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.