Replace M2Crypto with a better cryptography package for Volttron restricted code

[schandrika]

M2Crypto is not supported any more and breaks when python version gets updated. Tried out cryptography (https://cryptography.io/en/latest/) package. It works for the most the part but it does not have smime support. This is needed to generate .p7s files to include in the wheel file. We were not able to generate the p7s file usign openssl command line without any user prompting either. wheel file only supports p7s and JWS format signatures. Currently this is not a blocker as we are overriding the default Wheel file sign and verify methods and hence we could use alternate sign and verify method however the initial goal is to see if there is a different package or if there is a workaround to generate p7s file ( or JWS signature files) so that we don't have to override the sign and verify.