Add button to restart tor without restarting brave

[diracdeltas]

fix #14567

TEST PLAN:

1. start a local http server on port 9250, ex: "python3 -m http.server 9250 --bind 127.0.0.1"
2. start brave and open tor tab
3. wait for tor error to show
4. click 'retry' button
5. it should show 'connecting...' then show the error again
6. now kill the HTTP server from step 1
7. click 'retry' again. tor should connect this time.

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).
• 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. (Ask a Brave employee to help if you cannot access this document.)

Test Plan:

Reviewer Checklist:

• Request a security/privacy review as needed if one was not already requested.

Tests

• Adequate test coverage exists to prevent regressions
• Tests should be independent and work correctly when run individually or as a suite ref
• New files have MPL2 license header

[darkdh]

lgtm