add image export to footprint editor

[Thomas Pointhuber]

Export PNG/SVG should be added to the Footprint Editor as it is implemented for the Symbol editor, because this is a standard action when submitting a footprint to the official library. It would be nice to have those shortcuts for eeschema/pcbnew as well.

# Version Information

Application: kicad
Version: (6.0.0-rc1-dev-1139-g830c5e7db), debug build
Libraries:
    wxWidgets 3.1.1
    libcurl/7.62.0 OpenSSL/1.1.1 zlib/1.2.11 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.4) libssh2/1.8.0 nghttp2/1.34.0
Platform: Linux 4.18.16-arch1-1-ARCH x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.1.1 (wchar_t,wx containers) GTK+ 2.24
    Boost: 1.68.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.61.1
    Compiler: Clang 7.0.0 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=OFF
    KICAD_SCRIPTING_WXPYTHON=OFF
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

[Wayne Stambaugh (stambaughw)]

I am not sure how much effort this would be but it would be nice to implement it as part of 5.1

[KiCad Janitor (kicad-janitor)]

Fixed in revision f1f4473d8bde2809d4735311346ef7b4a5c09f7d
https://git.launchpad.net/kicad/patch/?id=f1f4473d8bde2809d4735311346ef7b4a5c09f7d