DSC parameters should be passed even when there is no config data file

This should also go into 11-stable.

Root cause is that unless you have the `configuration_data_script` attribute set to a valid .psd1 file, you can't pass parameters using the `flags` attribute to a DSC script. The current workaround without this fix is to specify a .psd1 file with empty hashes.

The issue is caused by the fact that configuration data is an argument to the script, and so are the parameters, and some logic around setting both the parameters and the configuration data as arguments would only set the parameters if the resource specified configuration data. The fix is to correct the check and always set parameters if they are specified. 

Regression tests were added as well that fail without this fix.