ShellPkg/Shell: Add double quotes to args with white space

https://bugzilla.tianocore.org/show_bug.cgi?id=332

When the ShellLib ShellExecute() API or the Shell
Protocol Execute() API are used to execute a
command, the arguments are parsed to produce the
Argc/Argv list in the Shell Parameters Protocol and
double quotes are removed from arguments that are
surrounded by double quotes.  This is the required
behavior of the Shell Parameters Protocol.

The ProcessCommandLine() function in the shell
implementation uses the Argc/Argv list from the
Shell Parameters Protocol to assemble a new command
line, but the double quotes that may have been
originally present for an argument are not preserved.

ProcessCommandLine() is updated to check if an
argument added to the generated command line
contains one or more white space characters, and
if it does, double quotes are added around the
argument.

Cc: Jaben Carsey <jaben.carsey@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Ruiyu Ni <Ruiyu.ni@intel.com>