REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2570
Add new Azure Pipeline definitions to build and run OvmfPkg with:
* Ubuntu GCC5
* Windows VS2019
Add PyTool based build of OvmfPkg
Add extdep for managing the iasl dependency
Add OvmfPkg.ci.yaml for Core CI
Add ReadMe.md for details and instructions
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Bret Barkelew <bret.barkelew@microsoft.com>