QmlDesigner: Add configuration for qsb shader generator tool

Added default ShaderTool configuration block to new project template
and use information specified there to generate qsb shaders.

The args property specifies command line argument for qsb tool.
The files property specifies files for which qsb tool is run for.

E.g.:

ShaderTool {
    args: "-s --glsl \"100 es,120,150\" --hlsl 50 --msl 12"
    files: [ "content/shaders/*" ]
}

Fixes: QDS-6590
Change-Id: I3bab0db21d20f486f9f25c1437a27ddb7fb47396
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Samuel Ghinet <samuel.ghinet@qt.io>

src/plugins/qmlprojectmanager/qmlproject.h

@@ -95,6 +95,8 @@ public:
     void setPrimaryLanguage(QString language);
     bool forceFreeType() const;
     bool widgetApp() const;
+    QStringList shaderToolArgs() const;
+    QStringList shaderToolFiles() const;
 
     bool addFiles(const QStringList &filePaths);