Allow Multiple Clients to Share A Cache

Problem/Motivation

When using multiple clients that extend the base api-client class (an instance of decoupled-router-client and json-api-client for example), there could be value in using a single cache instance shared between them rather then isolated cache instances for each.

Steps to reproduce

Proposed resolution

This might be possible today just by passing the same cache instance to each constructor. If so, we could consider making this the default for the json-api-client which creates a separate cache instance for both the main class and the instance of the decoupled-router-client that it uses.

Remaining tasks

User interface changes

API changes

Data model changes