Hart Refactor Improvements

* Testing
* Reviews
* Image processing
* Re-mapping schemas when we can specify once and use the spec
* Re-mapping the API contract
* We are overusing products as a context for items that don't belong there
* We are under-using products as a context for accessing products/lacking a clear interface for working with Products. We have a large API module, but could instead
* CMS HartToolsWeb huge view templates etc
* Paul's "refactor"

What are we trying to tackle first?

Testing, and then:

* The biggest problem first
* Products/API
* Reorg contexts
* Remove API module
* Images
* Context Remapping
* API contract
* many of the smallest problems first
* Codesmells
* Credo recommendations

Proposed process:

* Analyze
* Design
* Test
* Refactor

Notes

what I found reading through elixirforum was that most developers seem to deal with Jason serialization in one of two places:
in the Phoenix View layer a la https://hexdocs.pm/phoenix/views.html#rendering-json
deriving the Jason.Encoder protocol