MdeModulePkg/TerminalDxe: Optimize TtyTerm cursor motion

MdeModulePkg/TerminalDxe: Optimize TtyTerm cursor motion

For TtyTerm terminals, output a shorter escape sequence when possible
to move the cursor within the current line, and don't print any escape
sequence if the cursor is already at the correct position.  This
removes extra cursor motion activity at the EFI shell prompt,
improving performance.  It also makes it possible in many cases to
successfully use a terminal window which is taller than the driver's
mode setting (eg. 80x25.)

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Brian Johnson <bjohnson@sgi.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Feng Tian <feng.tian@intel.com>