ShellPkg: Fix Shell fail when execute command in ShellProtocol.Execute().

ShellPkg: Fix Shell fail when execute command in ShellProtocol.Execute().

When execute a command with tailing blank spaces in ShellProtocol.Execute() Shell will fail.
This patch move the TrimSpaces operation into ParseCommandLineToArgs function to fix the problem.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Yang Jadis <jadis.yang@intel.com>
Signed-off-by: Qiu Shumin <shumin.qiu@intel.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18491 6f19259b-4bc3-4df7-8a09-765794883524