Jws via factory

[glatzert]

An alternative implementation, which uses a base class and an extensible factory to create the signer.

[glatzert]

Since you already now the rest - probably you are only interested in the last commit (bb85e25)

[glatzert]

Closing this Pull-Request to realign with master and @ebekker s implementations.
My goal (to be discussed) will be to

1. Provide a JWSTool, which can easily be used an reloaded via an easy to use mechanism
2. Use the exisitng RSA and EC KeyGens to create that JWS Tool and Certificates.
3. Allow interop of all stored key material between PowerShell and Base module
4. Spin out Crypto as own DLL for less dependencies in PSCore Module.