ESD-30646: Add validation to prevent empty string scopes in client grant resource

[sergiught]

🔧 Changes

Prevent empty string values within scopes attribute of auth0_client_grant resource, so we avoid ending up with a panic.

📚 References

🔬 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 #793 (1b5aac2) into v1 (cf36419) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##               v1     #793   +/-   ##
=======================================
  Coverage   90.43%   90.43%           
=======================================
  Files          99       99           
  Lines       13188    13189    +1     
=======================================
+ Hits        11927    11928    +1     
  Misses        893      893           
  Partials      368      368           

Files Changed	Coverage Δ
internal/auth0/client/resource_grant.go	82.75% <100.00%> (+0.20%)	⬆️

[tyfrth]

Hey @sergiught and @willvedd! Stumbled on this by way of a community topic - It looks like it is possible to create a client grant with with an empty array for the scope param using the management API directly. Judging by the ESD, it's not possible to mirror that behavior here?