BaseTools/GenFw: Parse IBT/BTI support status from ELF note

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4405



When performing ELF to PE/COFF conversion, parse any notes sections to
decide whether the image supports forward CFI landing pads. This will be
used to set the associated DllCharacteristicsEx flag in a subsequent
patch.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>
Reviewed-by: Oliver Smith-Denny <osde@linux.microsoft.com>
Acked-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>