[Spike] - Use alternate front-end engine (replace RestServer)

[kjdelisle]

blocked by #753

DRAFT - Please re-groom

Story

Investigate what some of the tradeoffs would be in swapping out our RestServer for an alternate implementation using a technology like Express, Koa, Micro, etc.

Acceptance Criteria

• Create a new server implementation using one of the above technologies
• Create a new Router that leverages our openapi-spec package to generate routes using one of the routing libraries for the chosen framework (ex. if you selected koa, use koa-router to build the routes based on the existing api spec(s))

Questions to Answer

• Can we recycle core logic from our spec library between frameworks if we rewrite our router to use /foo/:id instead of /foo/{id}?
• What approach would a developer need to take to build a custom server for LoopBack that can still leverage our OpenAPI v3 libs?

[dhmlau]

Duplicate of #1071