OvmfPkg: add library to track boot option loading/starting on the console

Introduce the Platform Boot Manager Print Status Code Library (for short,
PlatformBmPrintScLib) class for catching and printing the LoadImage() /
StartImage() preparations, and return statuses, that are reported by
UefiBootManagerLib.

In the primary library instance, catch only such status codes that
UefiBootManagerLib reports from the same module that contains
PlatformBmPrintScLib. The intent is to establish a reporting-printing
channel within BdsDxe, between UefiBootManagerLib and
PlatformBmPrintScLib. Ignore status codes originating elsewhence, e.g.
from UiApp's copy of UefiBootManagerLib.

Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Julien Grall <julien.grall@linaro.org>
Cc: Ray Ni <ray.ni@intel.com>
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1515418
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

OvmfPkg/OvmfPkg.dec

@@ -45,6 +45,11 @@
   #                  access.
   PciCapPciSegmentLib|Include/Library/PciCapPciSegmentLib.h
 
+  ##  @libraryclass  Register a status code handler for printing the Boot
+  #                  Manager's LoadImage() and StartImage() preparations, and
+  #                  return codes, to the UEFI console.
+  PlatformBmPrintScLib|Include/Library/PlatformBmPrintScLib.h
+
   ##  @libraryclass  Access QEMU's firmware configuration interface
   #
   QemuFwCfgLib|Include/Library/QemuFwCfgLib.h