Split and refactor LedgerTable component

[cezaraugusto]

• 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).

Close #7379

Auditors: @bsclifton, @luixxiul

This PR addressed:

• Cleanup of preferences.js
• component refactor to Aphrodite
• make use of Flexbox whenever possible
• minor touch-ups regarding code indentation/readability
• Note: ledgerTable (where publishers are shown) was kept as-is since it uses sortableTable component, which refactor should be addressed in another issue (update: ledgerTable included)

Test Plan

• Ledger functionality should be kept the same:
  • Show only included sites should toggle between enabled/disabled publishers
  • Permanently remove a site should remove its row
  • Table should be kept sortable (untouched code)
  • Include toggle should be kept toggling enabled/disabled state

Note that verified state are fake and were hardcoded for preview purposes

[bsclifton]

Changes look good to me... however, unit tests fail. Now that we use Aphrodite, we need to put mocks in place for the SVG in tests which end up rendering this component

You can see which ones fail with npm run unittest

[cezaraugusto]

sorry I skip that. Updated

[bsclifton]

LGTM! 😄 thanks for updating the tests