Add Required and Preferred Authentication Methods to JITL SSHJob

Current Situation

• The JITL SSHJob supports passwors and public keys as Authentication Methods.
• There is no support for MFA with Required Authentication Methods.
• There is no support for Preferred Authentication Methods.

Desired Behavior

• The JITL SSHJob supports
  • Required Authentication Methods
    • Both password and private key have to be specified
    • The auth_method argument is specified as

      • password,publickey
        

      • publickey,password

    • The ordering of Authentication Methods is considered.
    • Both Authentication Methods have to be performed successfully.
  • Preferred Authentication Methods
    • Both password and private key have to be specified
    • The auth_method argument is specified as

      • password,publickey
        

      • publickey,password
        

    • The ordering of Authentication Methods is considered.
    • With the first Authentication Method being performed successfully, authentication is completed.