ShellPkg: Refactor Print logic out of main loop function

ShellPkg: Refactor Print logic out of main loop function

This has no change in the behavior of the LS command, but it removes the printing logic from the main recursive function.  This is the first step toward changing the code flow without affecting the look and feel.

The long term goal is correcting the recursion to be more clean and useful to users.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Erik Bjorge <erik.c.bjorge@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15179 6f19259b-4bc3-4df7-8a09-765794883524