URL and routing architecture

Problem/Motivation

Currently, Mercury Editor decorates the controller.entity_form core service with a custom class that checks to see if the requested entity form should be using Mercury Editor, and if so, redirects to the /mercury-editor/[uuid] route. Mercury Editor essentially takes over the "traditional" entity form route, making it impossible to access the default node entity route (e.g. node/[id]/edit).

Ideally, Mercury Editor would provide new routes for adding / editing content (e.g. "node/[id]/mercury-editor", "mercury-editor/node/add/[type]"), leaving the core routes (e.g. "node/[id]/edit") intact / accessible.

Proposed resolution

• Add new custom routes for adding / editing entities with Mercury Editor
• Alter entity definitions for ME-managed entities to replace core edit / create URLs with the ME-specific ones
• Create tests