Self-service cancel only

When event self-service cancellation is enabled, do not allow to transfer a registration.

Also does the following changes:

• Hide the Registration Date, Status and Role (it's TMI for most people)
• Change the page title to "Cancel Registration" (instead of "Self-service Registration Update")
• If it's a free event, it will also hide the fee column (because it's empty for free events, and looks like a bug)

Known issue: you will need to update the "Event - Online Registration" message template (Administration > Communication > Message Templates, then under "system messages"), because the default template says "you may transfer or cancel your registration", which will be confusing to users.