Refactor history tab CMSMain/HierarchyModelAdmin

[GuySartorelli]

Follow-up work from #2947

CMSMain has a history tab which only works for SiteTree. It should be made to work for any model which is versioned.

Benefits

• allows the history tab functionality to be used for all versioned models

Related

• SPIKE Analyse how LeftAndMain and CMSMain are put together and how they could work better #2933
• History viewer on other modeladmins silverstripe-versioned-admin#62

Acceptance criteria

• The history tab works for any model that has the Versioned extension applied
• The history tab is not present for models that don't have the Versioned extension applied
• The history tab can be used for multiple different models in the same project

TO BE DECIDED

• Do we want the versioned tab to still be handled in its own controller?
  • If not, should it be added by the controller, or by silverstripe/versioned-admin for all versioned records?

[emteknetnz]

It may make more sense to just get rid of the CMSMain history tab and instead get pages to use versioned-admin instead.

[GuySartorelli]

That's likely what this refactor would result in, yeah. That doesn't mean removing the tab so much as using the HistoryViewerField directly in a tab.