Acceptance criteria
As a user
When I visit Special:CommunityConfiguration
I will see a section labelled "CampaignEvents"
And with subtitle "Configuration options for the CampaignEvents extension"
When I click the section
I will be taken to a page with a field that allows me to select namespaces
And the field label should be "Valid event namespaces"
And the field should have no description and help text
Note: CommunityConfiguration settings are entirely declarative, and therefore we can't have custom validation such as "prevent removal of the Event: namespace".
