Use Winmark specific methods from cms-sdk for Winmark apps

When app is Winmark AND the page schema is cms-page-schema:

• use ContentManagementClient.WinmarkPages.ListWinmarkPages() to list Winmark CMS pages
• use ContentManagementClient.WinmarkPages.WinmarkCreateWinmarkPage() to create a new Winmark CMS page

If app is not Winmark OR the page schema is not cms-page-schema:

• use ContentManagementClient.Documents.ListDocuments() to list documents
• use ContentManagementClient.Documents.Create() to create a new document