Internalize tax forms API

[Betree]

Constraints

• We'll need to make sure both systems can co-exist, at least until all requested Dropbox Forms have been completed and we have Import Dropbox Forms data into Open Collective #7299.
• We want a feature flag to make sure we can release early and enable progressively.

Specs

• On the LegalDocuments table:
  • Add a service column to easily differentiate (opencollective|dropbox-forms)
• Add a submitLegalDocument mutation:
  • Parameters:
    • account
    • documentType
    • values
  • Throw if a legal document is already RECEIVED
  • Throw if not an account admin
  • Call the PDF service with the values to generate the PDF
  • Uploads the PDF to the dedicated S3 bucket
  • Encrypt & insert the values in the LegalDocuments table
• Add a legalDocuments field on Account that accepts a "requestStatus" parameter:
  • REQUESTED - to know if the account needs to complete a tax form
  • RECEIVED - to get the list of all submitted docs
• Rename HELLO_WORKS_AWS_S3_BUCKET to TAX_FORMS_AWS_S3_BUCKET
• Rename helloworks.documentEncryptionKey

[Betree]

Note: We may want to store part of the data unencrypted so that it can be filtered and displayed easily. Obviously, this should only happen with non-sensitive fields.

The best would be to look at the projected design for tax forms in the Host Dashboard. We can expect things like (list to be updated):

• submitterType (individual|business)
• formType (W9|W8|W8-BEN)