Add redirect modal for provider unavailable scenario

[emerick]

Resolves brave/brave-browser#25125

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally: npm run test -- brave_browser_tests, npm run test -- brave_unit_tests, npm run lint, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

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, 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-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

UI

Test Plan:

• Clean profile
• Enable Rewards
• Connect wallet to bitFlyer/Gemini/Uphold
• Confirm connection succeeds as expected
• Disconnect wallet
• Ask server team to temporarily disable provider linking on staging
• Connect wallet to bitFlyer/Gemini/Uphold
• Confirm that you get the "provider unavailable" modal and the wallet fails to connect
• Confirm that link takes you to Brave's server status page

[brave-builds]

A Storybook has been deployed to preview UI for the latest push

[szilardszaloki]

Hey @emerick, 🙂
Would you mind adding a screenshot of the new modal? Thanks!

[szilardszaloki]

Just ran into this myself 😄, this is what we get back:

{
  "code": 400,
  "data": {
    "validationErrors": null
  },
  "message": "Error validating Connecting Brave Rewards to Uphold is temporarily unavailable.  Please try again later"
}

[szilardszaloki]

👍🏻

[emerick]

SonarCloud failed due to a known code-duplication warning in our redirect modal code. Outside of that, CI passed on all platforms so this is ready for merge.