Reduce amount of SQL queries triggered by Nuget package's metadata

What does this MR do and why?

During an investigation of red error budget it was noticed that Nuget package's metadata endpoint GET /api/:version/groups/:id/-/packages/nuget/metadata/*package_name/index sometimes tiggers too many SQL queries 2000+ kibana (internal)

After an investigation a root cause of the issue was identified.

A good thing is that with this change we will improve both: group level and project level endpoints.

📸 Screenshots or screen recordings with explanation

🏠 With master branch

It triggers two SQL queries to load Packages::Package:

It triggers a SQL query to count Packages::Package:

It triggers N+1 queries for Packages::Package and associations, although some of them are grouped:

🚒 With this MR

It triggers the following SQL queries:

• SELECT Packages::Package
• SELECT Packages::PackageFile
• SELECT Packages::Nuget::Metadatum
• SELECT Packages::Tag
• SELECT Packages::DependencyLink
• SELECT Packages::Dependency
• SELECT Packages::Nuget::DependencyLinkMetadatum

🔬 How to set up and validate locally

1. First we need to prepare some data in rails console:

   def fixture_file_upload(*args, **kwargs)
     Rack::Test::UploadedFile.new(*args, **kwargs)
   end
   
   # Create packages with package's files
   package1 = FactoryBot.create(:nuget_package, project: Project.first)
   package2 = FactoryBot.create(:nuget_package, project: Project.first, name: package1.name)
   
   # Create package's tags
   [package1, package2].each do |pkg|
     ['tag1', 'tag2'].each { |tag| FactoryBot.create(:packages_tag, package: pkg, name: tag) }
   end
   
   # Create package's dependencies and package's dependencies links with NuGet metadatum
   [package1, package2].each do |pkg|
     dependency1 = Packages::Dependency.find_by(name: 'Newtonsoft.Json', version_pattern: '12.0.3') || FactoryBot.create(:packages_dependency, name: 'Newtonsoft.Json', version_pattern: '12.0.3')
     dependency2 = Packages::Dependency.find_by(name: 'Castle.Core', version_pattern: '4.4.1') || FactoryBot.create(:packages_dependency, name: 'Castle.Core', version_pattern: '4.4.1')
   
     FactoryBot.create(:packages_dependency_link, :with_nuget_metadatum, package: pkg, dependency: dependency1)
     FactoryBot.create(:packages_dependency_link, package: pkg, dependency: dependency2)
   end
   
   # Grab package's name and group's id to use later in the API request
   package1.name
   Project.first.group.id

2. Trigger API request

   curl --user <user>:<token> "http://gdk.test:3000/api/v4/groups/<group_id>/-/packages/nuget/metadata/<package_name>/index"

3. Verify SQL queries from app/presenters/packages/nuget/packages_metadata_presenter.rb in the development.log

   With master branch

   It triggers a separate SQL query for every package's file and package's metadatum.

   With this MR

   It triggers only one SQL query per data model.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #386051 (closed)