refactor(hook): nest API response and use Gorm preload to populate repo and build data

[ecrupper]

Continuing efforts from: #1111

Hook.Repo and Hook.Build.Repo are duplicative, so I pruned Hook.Build.Repo to only include Hook.Build.Repo.ID.

[codecov]

Codecov Report

Attention: Patch coverage is 92.43243% with 28 lines in your changes missing coverage. Please review.

Project coverage is 53.06%. Comparing base (f3b5f5c) to head (9fb6d42).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
api/webhook/post.go	0.00%	8 Missing ⚠️
database/hook/opts.go	0.00%	4 Missing ⚠️
mock/server/hook.go	0.00%	4 Missing ⚠️
api/hook/create.go	0.00%	2 Missing ⚠️
api/repo/create.go	0.00%	2 Missing ⚠️
database/hook/create.go	77.77%	1 Missing and 1 partial ⚠️
database/hook/update.go	77.77%	1 Missing and 1 partial ⚠️
api/admin/hook.go	0.00%	1 Missing ⚠️
api/hook/redeliver.go	0.00%	1 Missing ⚠️
api/hook/update.go	0.00%	1 Missing ⚠️
... and 1 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1147      +/-   ##
==========================================
+ Coverage   52.41%   53.06%   +0.65%     
==========================================
  Files         557      559       +2     
  Lines       19433    19722     +289     
==========================================
+ Hits        10185    10466     +281     
- Misses       8682     8688       +6     
- Partials      566      568       +2     

Files with missing lines	Coverage Δ
api/types/hook.go	100.00% <100.00%> (ø)
database/hook/count.go	100.00% <ø> (ø)
database/hook/count_repo.go	100.00% <ø> (ø)
database/hook/delete.go	100.00% <100.00%> (ø)
database/hook/get.go	88.88% <100.00%> (+5.55%)	⬆️
database/hook/get_repo.go	91.30% <100.00%> (+3.06%)	⬆️
database/hook/get_webhook.go	88.88% <100.00%> (+5.55%)	⬆️
database/hook/hook.go	52.63% <ø> (ø)
database/hook/last_repo.go	83.33% <100.00%> (+5.55%)	⬆️
database/hook/list.go	77.77% <100.00%> (+6.34%)	⬆️
... and 21 more