Cleanup: fix logic surrounding case contacts with no reimbursements

[elasticspoon]

Had an issue where users could not create case contacts. This PR was a bit of a hasty fix.

Causes

The issue was when an org has neither driving reimbursement nor additional expenses no parameters would be submitted on /case_contacts/:id/form/expense.

This meant that params would not contain case_contact and params[:case_contact][:status] = step.to_s unless @case_contact.active? would fail or later with params.require(:case_contact).permit(...)

Temp Fix

The temporary fix was to add <%= form.hidden_field :placeholder, value: true %> to ensure something is always submitted.

casa/app/views/case_contacts/form/expenses.html.erb

Line 5 in f8d7cf8

<%= form.hidden_field :placeholder, value: true %>

This is a terrible hacky fix.

Goals

We should find a better fix on both the system and request sides. From a user perspective it probably does not make sense that page is ever shown if a user can't do anything on it. Maybe it should not be shown?

On the other hand that might add a lot of complexity and instead we should be able to gracefully recover if a request is sent with no in the params case_contact.

I am not sure what the ideal solution is but both paths are probably worth exploring.