Introduce a new libexec/qt-internal-configure-examples script that allows to configure and build "standalone examples" just like "standalone tests". This is a prerequisite for using deployment api in examples for prefix builds, otherwise deployment api gets confused not finding various information that it expects from an installed qt. Because the various conditions in the build system for standalone examples are similar to standalone tests, introduce a new QT_BUILD_STANDALONE_PARTS variable and use that in the conditions. The variable should not be set by the user, and is instead set by the build system whenever QT_BUILD_STANDALONE_TESTS/EXAMPLES is set. Unfortunately due to no common file being available before the first project() call, in qtbase builds, per-repo builds and top-level builds, we need to duplicate the code for setting QT_BUILD_STANDALONE_PARTS for all three cases. Task-number: QTBUG-90820 Task-number: QTBUG-96232 Change-Id: Ia40d03a0e8f5142abe5c7cd4ff3000df4a5f7a8a Reviewed-by: Alexey Edelev <alexey.edelev@qt.io> Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>