Fixes #512

Description

Adds APIs for connecting Parseable with extendable modules

• registrations saved in .parseable.json
• configs saved in stream-name/.stream.json
• other routes are directly proxied to module path

Final Routes:

GET /api/v1/modules/ : get list of all module names
PUT /api/v1/modules/{module} : update registration for given module
DEL /api/v1/modules/{module} : delete registration for given module

PUT /api/v1/{module}/config/{logstream} : Update config for a given module and proxy to module config path
GET /api/v1/{module}/config/{logstream} : Get config object for a given stream. (Called by module)

ALL /api/v1/{module}/* : directly proxied to module by parseable

This PR has:

• been tested to ensure log ingestion and log query works.
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added documentation for new or modified features or behaviors.