Add DevTools style UI for replicant subscriptions

[realityforge]

It is currently very very difficult to work out which subscriptions are present on the client and thus very difficult to debug whether data not being present on the client is a problem with replicant or something else.

It would be nice to produce a dev tool that could be linked from the app to produce some basic information. The DevTool would have the following capabilities:

• Turn on/off replicant spy logging
• Use human readable graph names as well as numeric graph names
• List the set of AreaOfInterest objects and current state for AreaOfInterest.
• List the set of local subscriptions, whether they are explicit or not.
• The set of graph links as a dependency graph so can figure out why something is present on client.

In the future we could also add

• List of all entities in each subscription with human readable names for entities