Move 'Delete' button to delete a wiki page to the show page

At the moment, if you want to delete a wiki page, you have to:

• Click the Edit button
• Click on the Delete button

We can save one click and make the interface more discoverable if we move the Delete button in the edit form, to the wiki page show page.

Proposal

• Introduce a context menu under an icon button with vertical-ellipsis
• Put actions Page history and Delete page in context menu
• Delete page should be in $red-500 since it is a destruction action
  • This pattern is used for MR comments
• New page is should be styled as the solid blue primary action

If the user is not allowed to delete a page this action should not be visible.

This change makes the "Delete" action easier to access because it is available while in the reading state. This solution is less discoverable than introducing an icon button for delete but we assume that this action is not one that would happen often so does not need to be visible immediately.

Current Wiki	Consolidated actions	Consolidated actions menu