Implement campaigns update UI design

Created by: eseliger

• Current state column
• Stats bar, with stats about total diffStat, all changeset operations and added/removed/modified counts
• +- indicator
• Inline actions label
• Display change in base branch
• Commit changes column
• Expanded section
  • Tab headers with change indicators
  • Commits section with diffing
  • Changeset body ("Description") tab
  • Push indicator message
• Adjust changeset title color when different
• Campaign page: New stats bar design with total diffstat
• Design approval/follow-up work