Use field level validation errors

What does this MR do and why?

The Group Reporting Settings page uses bootstrap form errors.

This MR refactors that to pajamas style field level validation errors.

Issue: https://gitlab.com/gitlab-org/modelops/anti-abuse/team-tasks/-/issues/47

Screenshots or screen recordings

Before	After

How to set up and validate locally

Follow the steps outlined in this MR to test this locally.

MR acceptance checklist

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ee/app/views/groups/settings/reporting/show.html.haml

@@ -7,18 +7,23 @@
 %p
   = s_('GroupSettings|Automatically ban users who download more than the specified number of projects within the specified interval.')
 
-= form_errors(@group.namespace_settings)
+- amount_errors = @group.namespace_settings.errors.full_messages_for(:unique_project_download_limit)
+- interval_errors = @group.namespace_settings.errors.full_messages_for(:unique_project_download_limit_interval_in_seconds)
 
 = gitlab_ui_form_for @group, url: group_settings_reporting_path(@group) do |f|
-  .form-group
+  .form-group{ data: { testid: 'unique_project_download_limit' } }
     = f.label :unique_project_download_limit, s_('GroupSettings|Number of projects'), class: 'label-bold'
-    = f.number_field :unique_project_download_limit, value: @group.namespace_settings&.unique_project_download_limit, class: 'form-control gl-form-input'
+    = f.number_field :unique_project_download_limit, value: @group.namespace_settings&.unique_project_download_limit, class: ['form-control', 'gl-form-input', amount_errors.present? && 'is-invalid']
+    - amount_errors.each do |error|
+      .invalid-feedback= error
     .form-text.text-muted
       = s_("GroupSettings|The maximum number of unique projects a user can download within the specified interval before they're banned. Set to 0 to disable limiting.")
 
-  .form-group
+  .form-group{ data: { testid: 'unique_project_download_limit_interval_in_seconds' } }
     = f.label :unique_project_download_limit_interval_in_seconds, s_('GroupSettings|Interval (seconds)'), class: 'label-bold'
-    = f.number_field :unique_project_download_limit_interval_in_seconds, value: @group.namespace_settings&.unique_project_download_limit_interval_in_seconds, class: 'form-control gl-form-input'
+    = f.number_field :unique_project_download_limit_interval_in_seconds, value: @group.namespace_settings&.unique_project_download_limit_interval_in_seconds, class: ['form-control', 'gl-form-input', interval_errors.present? && 'is-invalid']
+    - interval_errors.each do |error|
+      .invalid-feedback= error
     .form-text.text-muted
       = s_('GroupSettings|Set to 0 to disable limiting.')