Panel fixes

[NejcZdovc]

Fixes panel favicon
Fixes panel create wallet
Fixes on restart panel show
Fixes panel not clearing after a switch

Resolves brave/brave-browser#1719
Resolves brave/brave-browser#1792
Resolves brave/brave-browser#1777
Resolves brave/brave-browser#1660

Ledger implementation brave-intl/bat-native-ledger#154

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:

• go to one site
• click on BAT logo
• click join now
• make sure that you see publisher data of the site that you are currently on
• restart browser
• click on BAT logo
• make sure that you see publisher data of the site that you are currently on

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

[jasonrsadler]

Getting a warning when creating wallet from OptIn screen:
Button component not provided an onClick handler as a prop (2 instances)

[NejcZdovc]

@jasonrsadler this is not related to this PR, but @ryanml fixed it in brave-ui, so is part of new version that will be updated in sep PR

[ryanml]

lgtm and works well!

[NejcZdovc]

master 9ff9849
0.57.x 06b8446
0.56.x 2a4bac4
0.55.x da82010

[bbondy]

Changed merged label to 0.56.x since this won't appear in 0.55.x hotfix2.