Clone build settings: re-populate build folder name

"Clone..." on the build settings page will clone the build configuration, which is a very nice feature. however it would be great to have a heuristics to fix the build folder name:

consider:

• cloning a configuration named "Debug" from /home/tim/build/build-qt6-dev-clang_18_qt_dev-Debug to "Debug-sanitizer" will lead to a folder named /home/tim/build/build-qt6-dev-clang_18_qt_dev-Debug2
• cloning this will give a /home/tim/build/build-qt6-dev-clang_18_qt_dev-Debug22
• cloning this will give a /home/tim/build/build-qt6-dev-clang_18_qt_dev-Debug222

however it is not unlikely that the `BuildConfig:Name` is actually part of the default build folder naming pattern. so if the build folder would be re-evaluated, and in my example above i'd end up with /home/tim/build/build-qt6-dev-clang_18_qt_dev-Debug-sanitizer