Unable to use custom endpoint that is not available via host=localhost or port=8545

[filippsen]

Motivation

I would like to configure the target host and port.

[filippsen]

Setting host to a value other than current origin is a problem on its own. Making it customizable implies custom CORS settings, as experienced in previous installments e.g. devkit.

Example:

Response to preflight request doesn't pass access control check:  
No 'Access-Control-Allow-Origin' header is present on the requested resource.  
Origin 'http://<host>:<port>' is therefore not allowed access.

Added to it, while it would be possible to expose the custom network endpoint defined in src/components/app/app.js, it would demand changes to user experience, on top of provisioning room in the interface for editing host and port.

All of the above apparently deviates from current intentions.