This commit adds support for images in protobuf messages.
The client can specify a path which will be used to load the image
and set the corresponding fields.
This makes the assumption that the RCP server runs on the same machine
as the client and they have access to the same files. This holds
currently for both status-react and status-console-client, we could
revisit and adds an upload if that changes in the future.
Andrea Maria Piana