Convert contribution analytics charts to Vue

What does this MR do and why?

Related issue: #375999 (closed)

Combines the three Contribution Analytics charts into a single Vue app, as opposed to three separate Vue/HAML hybrids like it currently is. The logic in contribution_analytics_bundle.js was migrated to new Vue components and a shared utils.js file. Headers & description were removed from show.html.haml and also added to these new components

Screenshots or screen recordings

UI should look the same before/after this change

How to set up and validate locally

1. Navigate to http://gdk.test:3000/dashboard/groups
2. Select a group
3. In the sidebar: Analytics -> Contribution

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.

qa/qa/ee/page/group/contribution_analytics.rb

@@ -5,9 +5,15 @@ module EE
     module Page
       module Group
         class ContributionAnalytics < QA::Page::Base
-          view 'ee/app/views/groups/contribution_analytics/show.html.haml' do
+          view 'ee/app/assets/javascripts/analytics/contribution_analytics/components/pushes_chart.vue' do
             element :push_content
+          end
+
+          view 'ee/app/assets/javascripts/analytics/contribution_analytics/components/merge_requests_chart.vue' do
             element :merge_request_content
+          end
+
+          view 'ee/app/assets/javascripts/analytics/contribution_analytics/components/issues_chart.vue' do
             element :issue_content
           end