Rework Contribution Privacy

[AMStrix]

Closes #448.

What this does

• authenticated users' contributions are never fully anonymous
• authenticated users can choose between private or public contributions
• private contributions will show up as "anonymous" on Proposal Detail view
• private contributions will be visible to to authenticated users on their Profile Funded tab, others will not see them
• unauthenticated users' contributions will be fully anonymous
• unauthenticated users' contributions for cancelled proposals will become donations
• logged in users' contributions for cancelled proposals will be refundable if they have set their refund address
• Proposal.no_refund has been removed
• Proposal.private has been added
• migration: all Contributions associated with a user will be public (contributions made while unauthenticated, or authenticated but having selected the unattributed checkbox)

Notes

• a "private" tag is used in the Profile > Funded view with a tooltip instead of the asterisk approach (see screenshot)

Testing

1. clear your local DB & flask db upgrade
2. create two users
   • User A + set user's refund address (settings > account > refund address)
   • User B + no refund address
3. create, stake, approve + publish a proposal
4. Anonymous Sign-out, then contribute 0.1 ZEC to the proposal
   • after clicking "Fund this project" ensure that the disclaimer for unattributed contributions shows up
   • review verbiage
   • click "I accept"
   • payment info shows up, click "I've sent it", see "Thank you" message and click "Done"
5. Refund Address/No Attribution Sign-in with User A, then enter 0.2 ZEC into the proposal contribution field
   • ensure that "Contribute without attribution" is set by default, leave it selected
   • click "Fund this project"
   • should see payment info, click "I've sent it", then "Done"
6. No Refund Address/Attribution Sign-in with User B, then enter 0.3 ZEC into contribution field
   • select "Attribute contribution publicly", click "Fund this project"
   • ensure Refund address setting modal appears, do not set a refund address
   • click "I don't want a refund, consider it a donation instead"
   • payment info should appear, click "I've sent it", then click "Done"
7. admin: Financials > Contributions should only have "staking 100% 0.025"
8. admin: Contributions > edit each of the pending contributions by setting the "Transaction ID" of each
9. admin: Financials > Contributions should have "funding 96% 0.6"
10. frontend: Proposal > Contributors (tab) should have three contributions and only one attributed to User B for 0.3 ZEC
11. frontend: Authenticate as User B and visit User A's Profile > Funded tab, there should be 0 contributions
12. frontend: Authenticate as User A and visit User A's Profile > Funded tab, there should be 1 private Contribution for 0.2 ZEC
    • visit User B's Profile > Funded tab, there should be 1 contribution for 0.3 ZEC
13. admin: from proposal detail "Cancel & refund" the proposal
14. admin: Financials > Contributions should have

    refunding 32% 0.2
    donation 64%  0.4
    staking   4%   0.025

15. admin: Home page should have one action item "ready to be refunded", click the action item link
    • there should be one Contribution from User A for 0.2 ZEC on the list page, click on the contribution
    • set a payment id (can be any string) and "Mark Refunded"
    • go back to Home, action item should be cleared
16. admin: Contributions > filter by "Donations", there should be two Contributions one from User B and the other from Anonymous
17. admin: Financials > Contributions should be:

    refunded 32% 0.2
    donation 64%  0.4
    staking   4%   0.025