print_diagnostic_information() misleading if runtime not installed

Description of issue

If I run python3 -c "import niscope; niscope.print_diagnostic_information()" on a Windows system that does not have NI-DCPower runtime installed, the output I get is:

Z:\>python3 -c "import nidcpower; nidcpower.print_diagnostic_information()"
OS:
    Name:      Windows
    Version:   10.0.18362
    Bits:      64
Driver:
    Name:      NI-DCPower
    Version:   Unknown
Module:
    Name:      nidcpower
    Version:   1.0.0
Python:
    Version:   3.6.8rc1 (v3.6.8rc1:cc3e73212a, Dec 12 2018, 00:15:46) [MSC v.1900 64 bit (AMD64)]
    Bits:      64
    Is_Venv:   False
    Installed Packages:
        zipp==1.0.0
        virtualenv==16.7.9
        tox==3.14.3
        toml==0.10.0
        six==1.11.0
        setuptools==40.6.2
        pytest==3.0.7
        pyparsing==2.4.6
        py==1.4.33
        pluggy==0.13.1
        pip==19.3.1
        packaging==20.0
        numpy==1.13.3
        nitclk==0.3.1
        niswitch==0.2.0.dev1
        niscope==1.1.5
        nimodinst==0.4.0.dev0
        nifgen==0.6.0.dev0
        nidmm==0.3.0.dev0
        nidcpower==1.0.0
        more-itertools==8.1.0
        markupsafe==1.0
        mako==1.0.7
        importlib-metadata==1.4.0
        filelock==3.0.12
        enum34==1.1.6
        colorama==0.4.3
        bs4==0.0.1
        beautifulsoup4==4.6.0

Specifically, the following is problematic:

Driver:
    Name:      NI-DCPower
    Version:   Unknown

1. I think "Driver" should be replaced with the more specific "Driver runtime".
2. Version should report "not installed" rather than "Unknown".

I think this is important because not having the runtime installed is probably going to be a common thing for a new nimi-python customer that's getting up and running. We should give them more concrete help.

Start by locating the nidcpower implementation of print_diagnostic_information() and reproduce the command on Windows without the NI-DCPower runtime installed. Update the diagnostic labels and missing-runtime version output as described, then verify that the output identifies the runtime as not installed rather than unknown.