Support SHA256, SHA512, SHA2 and SHA3

[NassimBtk]

Specification

SHA1 is deprecated since 2011 by NIST : https://www.tbs-certificates.co.uk/FAQ/en/microsoft_depreciation_sha1.html (2017 by Windows)

SHA256, SHA512, SHA2 and SHA3 are not supported by the WestHawk's SNMP API.

To implement each of the algorithms in the existing code, we have to perform the following changes:

• Implement a Digest class for the new algorithm. It should extend GeneralDigest
• Update the class AsnDecoderv3 to create the authentication and privacy credentials for SHA256, SHA3, etc ...
• Update the class AsnEncoderv3 to create the authentication and privacy credentials for SHA256, SHA3, etc ...
• Add a branch in the conditional statement to set the authenticate and authProtocolCode values for the new algorithm
• Add authentication methods, log messages and variables for the new algorithm in SnmpContextv3Basis
• Add a new constant for the new algorithm in SnmpContextv3Face
• Add authentication methods, log messages and variables for the new algorithm in SnmpContextv3Pool
• Implement authentication methods for the new algorithm in SnmpUtilities