Use Spec Language in RelyingPartyRegistration

Changed conventions to better follow the metadata descriptors that
the registration is meant to represent.

Closes gh-8777

saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/OpenSamlAuthenticationRequestFactory.java

@@ -57,7 +57,7 @@ public String createAuthenticationRequest(Saml2AuthenticationRequest request) {
 	@Override
 	public Saml2PostAuthenticationRequest createPostAuthenticationRequest(Saml2AuthenticationRequestContext context) {
 		AuthnRequest authnRequest = createAuthnRequest(context);
-		String xml = context.getRelyingPartyRegistration().getProviderDetails().isSignAuthNRequest() ?
+		String xml = context.getRelyingPartyRegistration().getAssertingPartyDetails().getWantAuthnRequestsSigned() ?
 			this.saml.serialize(authnRequest, context.getRelyingPartyRegistration().getSigningCredentials()) :
 			this.saml.serialize(authnRequest);
 
@@ -78,7 +78,7 @@ public Saml2RedirectAuthenticationRequest createRedirectAuthenticationRequest(Sa
 		result.samlRequest(deflatedAndEncoded)
 				.relayState(context.getRelayState());
 
-		if (context.getRelyingPartyRegistration().getProviderDetails().isSignAuthNRequest()) {
+		if (context.getRelyingPartyRegistration().getAssertingPartyDetails().getWantAuthnRequestsSigned()) {
 			List<Saml2X509Credential> signingCredentials = context.getRelyingPartyRegistration().getSigningCredentials();
 			Map<String, String> signedParams = this.saml.signQueryParameters(
 					signingCredentials,

saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/Saml2AuthenticationRequestContext.java

@@ -91,7 +91,7 @@ public String getRelayState() {
 	 * @return the Destination value
 	 */
 	public String getDestination() {
-		return this.getRelyingPartyRegistration().getProviderDetails().getWebSsoUrl();
+		return this.getRelyingPartyRegistration().getAssertingPartyDetails().getSingleSignOnServiceLocation();
 	}
 
 	/**