Replace PageHeader and PageHeaderTitle with same PageHeader component from ansible-ui repo (https://github.com/ansible/ansible-ui/wiki/PageHeader)

From: 

_{<PageHeader>
  <PageHeaderTitle title={'Job Explorer'} />
</PageHeader>}

To:

  _{<PageHeader title={'Job Explorer'} />}

Following files contains those components:

src/Containers/JobExplorer/JobExplorer.js

src/Containers/Clusters/Clusters.js

src/Containers/OrganizationStatistics/OrganizationStatistics.js

src/Containers/SavingsPlanner/Details/Details.js

src/Containers/SavingsPlanner/Add/index.js

src/Containers/SavingsPlanner/List/List.js

src/Containers/Notifications/Notifications.tsx

src/Containers/Reports/Details/index.tsx

src/Containers/Reports/List/List.tsx

Note: It may be possible that the component form ansible-ui repo will need some changes to fit all our headers correctly. If so it should be done as part of this issue.