Cleanup downloaders

Signed-off-by: Trial97 <alexandru.tripon97@gmail.com>

launcher/java/JavaRuntime.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <QDateTime>
+#include <QString>
+
+#include "java/JavaVersion.h"
+
+namespace JavaRuntime {
+
+enum class DownloadType { Manifest, Archive };
+
+struct Meta {
+    QString name;
+    QString vendor;
+    QString url;
+    QDateTime releaseTime;
+    QString checksumType;
+    QString checksumHash;
+    bool recommended;
+    DownloadType downloadType;
+    QString packageType;
+    JavaVersion version;
+};
+using MetaPtr = std::shared_ptr<Meta>;
+
+DownloadType parseDownloadType(QString javaDownload);
+QString downloadTypeToString(DownloadType javaDownload);
+MetaPtr parseJavaMeta(const QJsonObject& libObj);
+
+}  // namespace JavaRuntime