Publish student-finance-forms (smartdown edition)

The smartdown implementation of student finance forms has been tested
and are feature complete with the original rb/yml implementation.

* Remove the -transtion suffix, which distinguished it from the
  original version
* Change status to published
Delete original student finance flow

Now there the smartdown implmentation is complete.

 - remove the logic, copy and test
 - do the same for an old v2 that's knocking around
Update overseas-passports.yml

Removed option for ETD for children as per zen: https://govuk.zendesk.com/agent/#/tickets/833333
Merge pull request #1160 from gwenno/patch-2

Update overseas-passports.yml
Revert "Update overseas-passports.yml"
Merge pull request #1161 from alphagov/revert-1160-patch-2

Revert "Update overseas-passports.yml"
Merge pull request #1157 from alphagov/publish-student-finance-smartdown

Publish smartdown version of Student Finance Forms