Moves GetActivityInfoList and LoadPublisherInfo into ledger code

[NejcZdovc]

Resolves brave/brave-browser#4025

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 && npm run test-security) on
  • Windows
  • macOS
  • Linux
• 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

Test Plan:

plan 1

• clean profile
• enable rewards
• close rewards page (if opened)
• visit some site and stay there for 10+s
• go to rewards page and make sure that the site is in AC list

plan 2

• clean profile
• enable rewards
• add one site to ac table
• close that site and go to rewards page
• exclude it and then restore all sites
• go to that site and immediately open panel
• make sure that you see correct publisher info in the panel

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]

A few changes and/or questions

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