Use a list of executables to make sure that we don't miss any of the
applications used by Ladybird and its friends like WebDriver, and make
sure to install include all executables and their runtime dependencies.
Always call platform_init after there's a QApplication, because in the
installed configuration that's how we find the resources.
Try QCoreApplication::applicationDirPath() after looking in ./WebContent
for the WebContent process. In an installed configuration, ladybird and
WebContent will both be in $PREFIX/bin.
Add install rules for WebContent and its linked libraries, for if they
ever differ from ladybird's.
This setup should allow the package maintainers who are looking to
distribute ladybird on their distributions to use CMake to install
ladybird using cmake install rules rather than having to write their own
