Add Save as Version to Page Information menu

Many of our users miss a saving button. We don't promote that. Their need is to:

1. Create page
2. Modify it to their liking
3. Save the page once they reached a "milestone"
4. Colleagues then publish the "milestone" version or use it for approval
5. The main editor continues working on the page

Currently, the main editor must leave the page editor, go the Content Tree and create a version from there. They wish to create a version from within the page editor.

The menu is not existant yet.

Currently:

1. User must close the page editor
2. User goes to location of page
3. User selects page
4. User switches to the Timeline sidebar
5. User clicks the three dots at the bottom (see screenshot)
6. User clicks Save as Version
7. User fills in Label
8. User fills in Comment
9. User clicks Create
10. System saves Version

1. User clicks Page Information menu (see screenshot)
2. User clicks Save as Version
3. User fills in Label
4. User fills in Comment
5. User clicks Create
6. System saves Version