Implement Traffic Boost feature

[acicovic]

This issue will be kept up to date as we progress.

Phase 1

Phase 1 is about determining the feasibility of the feature, as well as identifying "what it takes" to land it.

Tasks

• Finalize feature design.
• "Break" the feature into conceptual parts, and write proof of concept code for each to verify implementability.
  • See if we'll need to bump the minimum WordPress version due to Gutenberg components, or WP functionality we require.
• Iterate the above as needed, depending on possible technical constraints that arise.