various small code fixes from clang-tidy, clazy and manual review

2 jobs for !1 with bringBackUpnp in 44 minutes and 26 seconds (queued for 1 minute and 8 seconds)
detached
Status Job ID Name Coverage
  Build
passed #72827
linux kf5-qt5 qt5.12

00:43:43

85.0%
passed #72826
reuse

00:00:42