refactor: Add external LLMCore lib (#334)

* feat: Add LLMCore submodule

pluginllmcore/RequestHandlerBase.hpp

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2024-2025 Petr Mironychev
+ *
+ * This file is part of QodeAssist.
+ *
+ * QodeAssist is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * QodeAssist is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with QodeAssist. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "RequestConfig.hpp"
+#include <QJsonObject>
+#include <QObject>
+
+namespace QodeAssist::LLMCore {
+
+class RequestHandlerBase : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit RequestHandlerBase(QObject *parent = nullptr);
+    ~RequestHandlerBase() override;
+
+    virtual void sendLLMRequest(const LLMConfig &config, const QJsonObject &request) = 0;
+    virtual bool cancelRequest(const QString &id) = 0;
+
+signals:
+    void completionReceived(const QString &completion, const QJsonObject &request, bool isComplete);
+    void requestFinished(const QString &requestId, bool success, const QString &errorString);
+    void requestCancelled(const QString &id);
+};
+
+} // namespace QodeAssist::LLMCore