IntelFrameworkModulePkg/BootMaint: Show "Change Boot order" page correctly

IntelFrameworkModulePkg/BootMaint: Show "Change Boot order" page correctly

Some boot options may be deleted in the "Delete Boot Option page",
But the data BootOptionOrder in BmmFakeNvData may not be updated.
So when user enter the "Change Boot Order" page, we should not always
get the BootOptionOrder in BmmFakeNvData, it will result in incorrect
UI behaviors. When the Boot Options have been saved,
we should get the BootOptionOrder through function GetBootOrder.

For driver option codes need to do the same change.

This patch is to fix the issue in bugzilla:
https://bugzilla.tianocore.org/show_bug.cgi?id=39

Cc: Eric Dong <eric.dong@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>