Change File Upload workflow to account for payments

[richard-jones]

File upload workflow should now be:

1. User uploads their file
2. User is presented with a page with the following:
   • Information about what they have uploaded (number of DOIs, etc)
   • What the cost of running the job will be
   • A confirmation step to run the job at the given cost, or to cancel the job
3. If the user cancels the job, we should ask for feedback on why they chose not to run it
4. If the user wishes to proceed with the job, we must collect some or all of the following invoice information (what are the minimum requirements?):
   • Invoice Contact Name
   • Invoice Contact Email
   • Invoice Contact Phone
   • Invoice Address
   • Purchase Order Number/Reference Number
5. The job is processed automatically, and the results page is locked/unlocked as per #167 while invoice details are checked.