ProjectExplorer: Add kitFilterText virtual method to ProjectImporter

This way a project importer implementation can modify the filterText edit
field from the Project setup page.

Task-number: QTCREATORBUG-29535
Change-Id: I22b3d613ff84111b918c4a4447cd5656d7c593b9
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/projectexplorer/projectimporter.h

@@ -36,6 +36,7 @@ public:
     virtual const QList<BuildInfo> import(const Utils::FilePath &importPath, bool silent = false);
     virtual Utils::FilePaths importCandidates() = 0;
     virtual Target *preferredTarget(const QList<Target *> &possibleTargets);
+    virtual QString kitFilterText() { return QString(); }
 
     bool isUpdating() const { return m_isUpdating; }
 

src/plugins/projectexplorer/targetsetuppage.cpp

@@ -569,8 +569,11 @@ void TargetSetupPagePrivate::doInitializePage()
     setupWidgets();
     setupImports();
 
-    selectAtLeastOneEnabledKit();
+    const QString filterText = m_importer ? m_importer->kitFilterText() : QString{};
+    kitFilterLineEdit->setText(filterText);
+    kitFilterLineEdit->filterChanged(filterText);
 
+    selectAtLeastOneEnabledKit();
     updateVisibility();
 }