EmulatorPkg/Unix: Rename GdbRun to GdbRun.sh

EmulatorPkg/Unix: Rename GdbRun to GdbRun.sh

https://bugzilla.tianocore.org/show_bug.cgi?id=1657

Add .sh file extension to the shell script GdbRun so
changes to this file will pass PatchCheck.py.

Also update all scripts that execute GdbRun to
execute GdbRun.sh instead.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Andrew Fish <afish@apple.com>
Cc: Ray Ni <ray.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>