This patch steals idea from D9710.
The difference in regard to the other patch is:
- right .json file is used for every plugin,
- no redundant paths are added in code (only build system is modified),
- no two different paths for installing plugins,
- all plugins get stored in bin directory after build.
More about it can be red on KF5CoreAddonsMacros
Loading plugins without plugins path set is not working for me, but I think it should work for someone according to QCoreApplication::libraryPaths()