Verify all `niscope` methods/properties related to "CableSense™" feature are present

Description of issue

When reviewing PR #1252 I noticed property niscope.Session.cable_sense_mode exists but method niscope.Session.cable_sense_signal_start does not. These are both related to recent NI-SCOPE feature CableSense™.

We need to review and ensure we are presenting all the functionality correctly.

System report

C:\Users\kirsch>python3 -c "import niscope; niscope.print_diagnostic_information()
OS:
    Name:      Windows
    Version:   10.0.18362
    Bits:      64
Driver:
    Name:      NI-SCOPE
    Version:   19.1.0.49152
Module:
    Name:      niscope
    Version:   1.1.5
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==20.0.2
        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==1.1.5
        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

Start by reviewing the niscope.Session.cable_sense_mode property and comparing the Session API with the NI-SCOPE CableSense functionality referenced in PR #1252. Verify whether cable_sense_signal_start and the other CableSense methods and properties are presented correctly; done means the exposed API covers the required functionality consistently.