ShellPkg: Refactor string manipulation in cp command

This patch replaces StrCpy with StrnCpy or refactors out the usage of StrCpy through some other means.
This patch replaces StrCat with StrnCat or refactors out the usage of StrCat through some other means.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15771 6f19259b-4bc3-4df7-8a09-765794883524
Correct AsciiStrnCpy.

Contributed-under: TianoCore Contribution Agreement 1.0

Signed off by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed by: Eric Dong <eric.dong@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15772 6f19259b-4bc3-4df7-8a09-765794883524
Update network stack code to use StrnCpy instead of StrCpy.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Fu, Siyuan <siyuan.fu@intel.com>
Reviewed-By: Dong, Eric <eric.dong@intel.com>
Reviewed-by: Wu, Jiaxin <jiaxin.wu@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15773 6f19259b-4bc3-4df7-8a09-765794883524
clang warns on guard macro not matching in .h file.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Andrew Fish <afish@apple.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15774 6f19259b-4bc3-4df7-8a09-765794883524