Feature/restructure edit api backend form. Closes #799

[brylie]

When debugging #799, I realized that authorization logic was being applied in the router. This PR moves the authorization logic to the template, so that we can check for template level subscriptions when authorizing users.

Additionally, this is a significant restructuring of the editApiBackend template:

• renamed/restructured files and folders
  • handle subscription in parent template
    • pass in named data context to sub-template
  • all camel case file names for consistency and sorting
  • short and semantic sub-directories (add/edit)
• removed 'add api backend (advanced)' feature
  • removed unused route
  • form type (insert or update) helper removed

[brylie]

@apinf/developers please review.

[55]

Looks good, merging.