Launcher Auth (#450)

* Launcher Auth

* Finish auth

* final fixes

theseus/src/api/pack/install_mrpack.rs

@@ -168,6 +168,7 @@ pub async fn install_zipped_mrpack_files(
                         }
                     }
 
+                    let creds = state.credentials.read().await;
                     let file = fetch_mirrors(
                         &project
                             .downloads
@@ -176,8 +177,10 @@ pub async fn install_zipped_mrpack_files(
                             .collect::<Vec<&str>>(),
                         project.hashes.get(&PackFileHash::Sha1).map(|x| &**x),
                         &state.fetch_semaphore,
+                        &creds,
                     )
                     .await?;
+                    drop(creds);
 
                     let path =
                         std::path::Path::new(&project.path).components().next();