Shows only completed tips in tip list

[NejcZdovc]

Resolves brave/brave-browser#8945

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-Protection-Mode
  • 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:

• enable rewards
• connect KYC uphold wallet
• tip Khanacademy.org
• make sure that tip is not shown in tips list
• make sure that tip is shown in pending list

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.

[NejcZdovc]

this change fixes tip table display

[NejcZdovc]

this change fixes pending contribution not logged

[LaurenWags]

Verified using

Brave	1.8.60 Chromium: 81.0.4044.83 (Official Build) nightly (64-bit)
Revision	5718ca617723806b9aacfb41108a0d911d1bde74-refs/branch-heads/4044@{#853}
OS	macOS Version 10.14.6 (Build 18G3020)

• Verified test plan on staging env (not production). Used ddg as connected publisher for test and 3zsistemi.si as KYC'd publisher.

• Confirmed one time tip to connected publisher (DDG) goes to 'Pending Contributions' list and not to Tips panel. Confirmed wallet balance does not decrease.

• Confirmed one time tip to KYC'd publisher (3zsistemi) is listed in Tips panel and is contributed. Confirmed wallet balance decreases. Confirmed tip displays on summary.

• Confirmed recurring tip to connected publisher (DDG) goes to 'Pending Contributions' list. Confirmed wallet balance does not decrease.

• Confirmed recurring tip to KYC'd publisher (3zsistemi) is contributed. Confirmed wallet balance decreases. Confirmed recurring tip displays on summary.