[gitlab-org/gitlab] Refactor billings page view logic to use ViewComponent for namespace state rendering

### ROOT CAUSE The billings page uses inline conditional logic to determine the view, and the controller duplicates this logic in a helper method. This duplication complicates maintenance and introduces tech debt as new namespace states are added. ### CODE FIX 1. **Create a ViewComponent to encapsulate rendering logic**: - Create a new component `NamespaceBillingComponent` under `app/components/groups/billing/`. - Use this component to centralize the conditional rendering logic. 2. **Refactor the Controller**: - Remove the `free_or_trial_namespace?` helper method as the component now handles the state check. 3. **Update the View**: - Replace the inline conditionals with the ViewComponent. **New Code:**

haml
# app/components/groups/billing/namespace_bills_component.rb
class NamespaceBillsComponent < ViewComponent::Base
  def call
    if @group.paid? && !@group.trial?
      # Render paid plan UI
    else
      # Render free/trial UI
    end
  end
end


**Controller Update**:
ruby
# controllers/groups/bills_controller.rb
def index
  @namespace_bills = NamespaceBillsComponent.new(group: @group, plans_data: @plans_data)
end


**View Update**:
haml
# app/views/groups/bills/index.html.haml
= NamespaceBillsComponent.new(group: @group, plans_data: @plans_data)


This refactoring centralizes the rendering logic, reduces duplication, and improves maintainability.