Wish: Group selection of RefDefs on Silk layers in High Contrast mode (lp:#1797083)

Original report created by Tim N. Tashpulatov (tim-tashpulatov)

When cleaning up Silk layers in High Contrast mode, it is impossible to
select a group of RefDefs other than by Shift+Clicking. Would be handy to
enable them for selecting just like PCB Text since their footprints are
greyed and obviously user wants to fiddle with text.

Attached picture shows selecting a group of RefDefs and PCB Text. Only ABC
text is being selected (not clearly seen on the shot but it is highlighted
after selection is done).

Application: kicad
Version: (5.0.0), release build
Libraries:
    wxWidgets 3.0.3
    libcurl/7.54.1 OpenSSL/1.0.2l zlib/1.2.11 libssh2/1.8.0 nghttp2/1.23.1
librtmp/2.3
Platform: Windows 7 (build 7601, Service Pack 1), 64-bit edition, 64 bit,
Little endian, wxMSW
Build Info:
    wxWidgets: 3.0.3 (wchar_t,wx containers,compatible with 2.8)
    Boost: 1.60.0
    OpenCASCADE Community Edition: 6.8.0
    Curl: 7.54.1
    Compiler: GCC 7.1.0 with C++ ABI 1011

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_ACTION_MENU=OFF
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

Original tags: pcbnew