Deploy ui.rc file as Qt resource
Possible since KF 5.4, done almost everywhere now.
Some advantages:
- user cannot accidentally delete it when messing with installs, default data is always baked into the binary (like other, more simple default config data).
- data of a qrc "file" is already mapped into the memory as part of the loaded binary, so besides some memory page changes the side-effect are lower compared to loading data from a separate file on the filesystem (sadly forgot where I read some closer look at that, but something about less system calls involved as well as side-effects on the filesystem cache)
- less files to package, less packager work (of course more one-time work on a change like this to adapt :) )