feat(nextcloud): Expose custom HttpClient

Signed-off-by: jld3103 <jld3103yt@gmail.com>

packages/nextcloud/lib/src/client.dart

@@ -30,6 +30,7 @@ class NextcloudClient extends DynamiteClient {
     final String? language,
     final AppType appType = AppType.unknown,
     final String? userAgentOverride,
+    super.httpClient,
     super.cookieJar,
   }) : super(
           baseHeaders: language != null ? {'Accept-Language': language} : null,