YADE Passphrase element should map to the new flat parameter passphrase instead of password

Current Situation

• The configuration element Passphrase used by the AuthenticatedMethodPublickey will be internally mapped to the flat parameter password.
• In case of the Preferred- or RequiredAuthentications this parameter override the value of the AuthenticationMethodPassword / Password parameter.

Desired Behaviour

• The Passphrase element should maps to the new flat parameter passphrase.
• Use of Passphrase includes support for use of a Credential Store.
• The YADE XSD schema should be adjusted to reflect use of passphrase.