Allow to specify if "Library Browser" or "Choose Symbol/Footprint" is default (lp:#1813880)

Original report created by Thomas Pointhuber (pointhi)

At the moment we have 2 different ways to select footprints (as well as
symbols). The behaviour is not unified, in fact some dialog uses different
dialogs by default. Users can switch to the other dialog manually, but it
would be a good idea to keep a consistent default.

Personally, I prefer "Choose Footprint" which looks like the symbol
chooser, and allows to filter.

# Version Information

Application: kicad
Version: (6.0.0-rc1-dev-1641-g872f0eb44), debug build
Libraries:
    wxWidgets 3.1.1
    libcurl/7.63.0 OpenSSL/1.1.1a zlib/1.2.11 libidn2/2.1.0 libpsl/0.20.2
(+libidn2/2.1.0) libssh2/1.8.0 nghttp2/1.35.1
Platform: Linux 4.20.4-arch1-1-ARCH x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.1.1 (wchar_t,wx containers) GTK+ 3.24
    Boost: 1.69.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.63.0
    Compiler: Clang 7.0.1 with C++ ABI 1002

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=ON
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

Original tags: eeschema pcbnew ui