Disable search on 404 page

[mariuszostrowski]

Describe the bug:
Please add an option to disable search form on 404 page

Expected behavior:

Screenshot(s):

Priority (select one):

• High - Functional blocker
• Medium - Doesn't work as expected
• [*] Low - Not a big deal but we'd want to get to this eventually

[jrtashjian]

Closing this issue as it will be addressed in the Full Site Editing work currently underway in Go.