Support freezing of categories, courses, activities contexts and their content

Create some sample data. You will need: Course categories, and nested course categories Courses Users Blocks in a course category Blocks in a course Login as admin Turn editing on For a course, category, and a block: Open the dropdown cog Confirm that there is no option to "Freeze this context" Navigate to Site administration => Development => Experimental settings Enable " Context freezing " and save changes For a course, category, and a block: Open the dropdown cog Confirm that there is now an option to " Freeze this context " Open the top course category Open the dropdown cog Open the Freeze this context page and freeze the context Confirm that you can still see the " Freeze this context " entry in the menu Confirm that all edit actions have been removed from the dropdown Confirm editing has been disabled Confirm that you cannot turn editing on Open a sub-category Confirm that you cannot see the " Freeze this context " entry in the menu Confirm that all edit actions have been removed from the dropdown Confirm editing has been disabled Confirm that you cannot turn editing on Open a course within the category Confirm that you cannot see the " Freeze this context " entry in the menu Confirm that all edit actions have been removed from the dropdown Confirm editing has been disabled Confirm that you cannot turn editing on Open a forum within the course Confirm that you cannot see the " Freeze this context " entry in the menu Confirm that all edit actions have been removed from the dropdown Confirm editing has been disabled Confirm that you cannot turn editing on Confirm that you cannot edit, delete, create, or reply to any posts (note: You can still manage your subscriptions* Navigate back the original category Unlock the category from within the menu Navigate to the course Lock the course Confirm that you can still see the " Freeze this context " entry in the menu Confirm that all edit actions have been removed from the dropdown Confirm editing has been disabled Confirm that you cannot turn editing on Open a forum within the course Confirm that you cannot see the " Freeze this context " entry in the menu Confirm that all edit actions have been removed from the dropdown Confirm editing has been disabled Confirm that you cannot turn editing on Confirm that you cannot edit, delete, create, or reply to any posts (note: You can still manage your subscriptions* Confirm that all edit actions have been removed from the dropdown Confirm editing has been disabled Confirm that you cannot turn editing on Navigate to a different course Confirm that you can still see the " Freeze this context " entry in the menu Confirm that you can still edit the course and activities within it Navigate back to the original course and unfreeze it Open the forum and lock it Confirm that you can still see the " Freeze this context " entry in the menu Confirm that all edit actions have been removed from the dropdown Confirm editing has been disabled Confirm that you cannot turn editing on Confirm that you cannot edit, delete, create, or reply to any posts (note: You can still manage your subscriptions* Confirm that all edit actions have been removed from the dropdown Confirm editing has been disabled Confirm that you cannot turn editing on Navigate back to the forum and unfreeze it Open the course Open the dropdown menu for a block and freeze that block Confirm that you can still see the " Freeze this context " entry in the menu Confirm that all edit actions have been removed from the dropdown