engine: Rename providerId to networkProviderId in add/update host actions

The property is renamed due to a new provider which was added with the
same name for the sake of Foreman integration.

In addition, type was added to provider to clear few eclipse warnings.

Change-Id: I9cdaddbfd41223b9eb32b52ebfb9333709c0440d
Signed-off-by: Moti Asayag <masayag@redhat.com>