SecurityPkg/DxeImageVerificationLib: Add AUTH_SIG_NOT_FOUND Action

SecurityPkg/DxeImageVerificationLib: Add AUTH_SIG_NOT_FOUND Action

Add the AUTH_SIG_NOT_FOUND Action to the Image Execution Info Table
when the Image is signed but signature is not allowed by DB and the
hash of image is not found in DB/DBX.

This is documented in the UEFI spec 2.10, table 32.5.

This issue is found by the SIE SCT with the error message as follows:
SecureBoot - TestImage1.bin in Image Execution Info Table with
SIG_NOT_FOUND. --FAILURE
B3A670AA-0FBA-48CA-9D01-0EE9700965A9
SctPkg/TestCase/UEFI/EFI/RuntimeServices/SecureBoot/BlackBoxTest/
ImageLoadingBBTest.c:1079:Status Success

Signed-off-by: Nhi Pham <nhi@os.amperecomputing.com>
Reviewed-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>