Mark tokens as spendable if contribution failes

[NejcZdovc]

Resolves brave/brave-browser#10522

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Android
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that these changes pass automated tests (unit, browser, security tests) on
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that all lint errors/warnings are resolved (npm run lint)
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Yes or QA/No) to include the closed issue in milestone
• Public documentation has been updated as necessary. For instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-compatibility-issues-with-tracking-protection
  • https://github.com/brave/brave-browser/wiki/QA-Guide

Test Plan:

• defined in the issue

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on.
• All relevant documentation has been updated.

[emerick]

LGTM

[NejcZdovc]

CI failed on test-install, all good

[LaurenWags]

Verified using PR builder build (https://bravesoftware.slack.com/archives/CMH8DU4TF/p1593550207257100)

Scenario 1

• Verified STR from issue
• Confirmed able to tip 20 BAT in step 7 and tip looks successful:

[14614:775:0701/074810.055567:VERBOSE1:contribution.cc(399)] Creating contribution(blinded) for 0 type RewardsType::ONE_TIME_TIP
[14614:775:0701/074810.061567:VERBOSE1:contribution.cc(267)] Timer will start in 9
[14614:775:0701/074810.103554:VERBOSE5:ledger_impl.cc(471)] 
[ REQUEST ]
> URL: https://grant.rewards.bravesoftware.com/v1/suggestions

[ RESPONSE - OnRedeemTokens ]
> Url: https://grant.rewards.bravesoftware.com/v1/suggestions
> Result: Success

AC was stopped right after DDG so the other AC publishers have a contributed_amount of 0 and the 1 time tip is listed at the bottom:

VG tokens were released from reserve process to be able to be used for the 1 time tip (first 5 tokens were for DDG AC, remaining used were used for the 1 time tip)

• Confirmed able to tip 1 BAT successfully as in step 8

Scenario 2 - same as 1 but use a restored anon wallet instead of UGP grant in step 2 (and I adjusted monthly budget to be 10 BAT instead of 20)

• Confirmed able to tip 5 BAT in step 7 and tip looks successful:

[14781:775:0701/080829.143039:VERBOSE1:contribution.cc(399)] Creating contribution(anonymous) for 0 type RewardsType::ONE_TIME_TIP
[14781:775:0701/080829.148819:VERBOSE1:contribution.cc(267)] Timer will start in 6
[14781:775:0701/080829.149109:VERBOSE5:ledger_impl.cc(471)] 
[ REQUEST ]
> URL: http://payment.rewards.bravesoftware.com/v1/orders

AC was stopped right after first publisher so the other AC publishers have a contributed_amount of 0 and the 1 time tip is listed at the bottom:

SKU tokens used for the tip are listed in unblinded_tokens but as discussed previously, tokens obtained for the auto contribute which were not used are still listed but not part of your balance/cannot be used (https://bravesoftware.slack.com/archives/CB0KCRCQN/p1593520104213200?thread_ts=1593519527.212600&cid=CB0KCRCQN)