feat: client | network group assignment alignment and test

[1riatsila1]

Description

Align NetworkGroupAssignment and create a test for it

Related Issue(s)

[codecov]

Codecov Report

Attention: Patch coverage is 20.25316% with 63 lines in your changes missing coverage. Please review.

Please upload report for BASE (main@a3cc17c). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...nt/model_network_group_assignments_get_response.go	17.10%	60 Missing and 3 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #36   +/-   ##
=======================================
  Coverage        ?   35.38%           
=======================================
  Files           ?       45           
  Lines           ?     4720           
  Branches        ?        0           
=======================================
  Hits            ?     1670           
  Misses          ?     2842           
  Partials        ?      208           

Files with missing lines	Coverage Δ
pkg/config-api-client/api_configuration.go	52.59% <100.00%> (ø)
pkg/config-api-client/client.go	22.22% <ø> (ø)
pkg/config-api-client/configuration.go	44.70% <ø> (ø)
pkg/config-api-client/model_error_detail.go	0.00% <ø> (ø)
pkg/config-api-client/model_error_response.go	0.00% <ø> (ø)
pkg/config-api-client/model_group.go	25.80% <ø> (ø)
pkg/config-api-client/model_groups_get_item.go	12.00% <ø> (ø)
pkg/config-api-client/model_groups_get_response.go	15.55% <ø> (ø)
pkg/config-api-client/model_groups_post_request.go	17.10% <ø> (ø)
...kg/config-api-client/model_groups_post_response.go	14.42% <ø> (ø)
... and 17 more