feat: use the homeserver url from the wellknown file for JWT check (MESSENGER-6777)

RiotSwiftUI/Modules/Authentication/Common/Service/MatrixSDK/AuthenticationService.swift

@@ -205,6 +205,20 @@ class AuthenticationService: NSObject {
         delegate?.authenticationService(self, didReceive: token, with: transactionID) ?? false
     }
     
+    /// BWI: #6777 use baseURL for JWT handling
+    func getBaseURL(_ homeserverAddress: String) async -> String? {
+        guard let homeserverURL = URL(string: homeserverAddress) else {
+            return nil
+        }
+        
+        guard let wellKnown = try? await wellKnown(for: homeserverURL) else {
+            return nil
+        }
+        
+        return wellKnown.homeServer.baseUrl
+    }
+    /// BWI END
+    
     // MARK: - Private
     
     /// Query the supported login flows for the supplied homeserver.