Add FactoryBot DSL for end-to-end Resources

What does this MR do and why?

Adds FactoryBot DSL for end-to-end resources.

Adds three factories:

1. Groups
2. Projects
3. Issues

Each factory a representative of their respective QA::Resource::* class.

Example

Instead of writing the following:

RSpec.describe 'my test' do
  let(:project) do
    Resource::Project.fabricate_via_api! do |project|
      project.name = 'My Project'
    end
  end

  let(:issue) do
    Resource::Project.fabricate_via_api! do |issue|
      issue.name = 'My Issue'
      issue.confidential = false
    end
  end
end

We become closer with how backend/frontend are familiar with fabricating resources in lower-level tests by using FactoryBot.

RSpec.describe 'my test' do
  let(:project) { create(:project, name: 'My Project') }
  let(:issue) { create(:issue, :confidential, name: 'My Issue') }
end

Closes gitlab-org/quality/quality-engineering/team-tasks#1894 (closed)

Screenshots or screen recordings

pry(#<RSpec::ExampleGroups::Plan::IssueComments>)> issue
{ "name": "issue", "description": "description" }
pry(#<RSpec::ExampleGroups::Plan::IssueComments>)> issue.class
QA::Resource::Issue

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Checkout this branch
2. $ bundle exec bin/qa Test::Instance::All http://gdk.test:3000 -- qa/specs/features/browser_ui/2_plan/issue/comment_issue_spec.rb:14

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.