Add rewards notification for insufficient funds

[emerick]

Fixes brave/brave-browser#1479
Requires brave/brave-ui#301

Notify the user about upcoming contribution when they don't have
enough funds to cover the donations. The notification occurs 3 days
before the contribution will be made.

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
  • Windows
  • macOS
  • Linux
• Verified that these changes pass automated tests (npm test brave_unit_tests && npm test brave_browser_tests) on
  • Windows
  • macOS
  • Linux
• 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

Test Plan:

• Delete any existing profile
• Launch Brave
• Enable Rewards
• Ensure that existing balance is less than contribution amount
• Wait > 1 day (every day, we check if notifications need to be displayed)
• Rewards icon should be badged and should contain a notification like this:

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

[NejcZdovc]

@emerick can you please rebase

[emerick]

@emerick can you please rebase

Done!

[NejcZdovc]

this one is currently blocked on 0.35 version of UI to be added.

[NejcZdovc]

master (0.61) 3f3d57c
0.60 b0faacc