Enable usage of Kura DeploymentService customization from Kapua

[pintify]

Is your feature request related to a problem? Please describe.
The DeploymentService on Kapua allows you to create a customized behavior for a download based on a parameter, request.type which routes the behavior before and after a download (and a an installation). However, the deployment requests available in the Kapua API REST does not allow such thing and you must create a whole new Custom request on your own just to add this parameter.

Describe the solution you'd like
An additional parameter in the Packages download request of the REST API:

It could include an additional parameter called request.type to enable this feature:

Describe alternatives you've considered
As said, we're currently forced to do this via the generic request url:

[pintify]

In fact, I think it would be also interesting to enable the dp.install.system.update which is already defined in the model but the logic to fill it from the request is missing: