BaseTools: sets are faster to check via "in" due to hashing

BaseTools: sets are faster to check via "in" due to hashing

switch list to set:
1)we dont care about order
2)we only check for membership.

then remove ".keys()" from dict looping:
allow generators opportunity to optimize

Cc: Liming Gao <liming.gao@intel.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>