feat(datasource): PoC implementation for the CloudSigma server context
feat(*): Add the server context datasource in the main flags
refactor: Add ExtractIPs method to the Datasource interface
test: Add tests and simplify the userdata crunching
refactor: Fetch byte arrays from the serial console

That allows me use native IP guessing
feat(datasource/server_context): Put cepgo in the source tree
refactor: Remove leftover ExtractIPs method in remoteFile