McuSupport: Separate toolchain file and compiler packages

Toolchain package represents information about compiler and toolchain
file (.cmake). This information is parsed from JSON and used for Kit
creation. This includes cmake variables, path to compiler. This patch
extracts information about toolchain file into separate McuPackage.

Change-Id: Id165bdc5afa5d7cf5b5c96620e11cb878254c181
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/mcusupport/mculegacyconstants.h

@@ -0,0 +1,33 @@
+/****************************************************************************
+**
+** Copyright (C) 2022 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#pragma once
+
+namespace McuSupport::Constants {
+
+const char QUL_TOOLCHAIN_CMAKE_DIR[] = "lib/cmake/Qul/toolchain/";
+const char QUL_ENV_VAR[] = "Qul_ROOT";
+
+} // namespace McuSupport::Constants