Feature: Get arguments from headers

[onuryilmaz]

It is possible to pass credentials or secrets via --permit-arguments as URL parameters: http://127.0.0.1:8080/?key=value

In order to pass critical information, it should be possible to pass inside headers: Arguments: key=value

In the server side, these parameters can also be added to the URL parameters while calling New(params map[string][]string) at backend/localcommand/factory.go#L40