[RFE] Stop special handling of mime extensions in the API

Previously we treated things like /v1/nodes/test.1 as node with name "test" returned as man page. This obvious misbehavior was fixed in https://bugs.launchpad.net/ironic/+bug/1643995. However, we still treat /v1/nodes/test.json as node "test" if it exists and only fall back to node "test.json" if it does not.

This RFE suggests introducing an API version where any special treatment of .json is disabled in the API. So, in this version /v1/nodes/test.json will only mean node with name "test.json", and /v1/nodes.json will be HTTP 404.