ShellBinPkg: Remove ShellBinPkg

ShellBinPkg: Remove ShellBinPkg

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1675

Remove ShellBinPkg from edk2.
If developers work on current edk2 master and still want to use Shell
binary after this removal, they can get it from source code in the Assets
part of edk2-stable201903 tag release page.
And from next release (edk2-stable201905 tag), we will publish all Shell
binaries to the according Assets part directly.
link: https://github.com/tianocore/edk2/releases
Cc: Jaben Carsey <jaben.carsey@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>
(cherry picked from commit 62d8b6004616a6d9b06afa83974be30eb951c679)