Fixes the override highlights in per-game settings from looking weird when viewed on the Dark or Midnight Blue themes by setting QLabels to have transparent backgrounds by default.
Also apparently adds a newline to the end of the Dark theme's qss file.
Qdarkstyle's qss file uses an overflow property.
According to `https://doc.qt.io/qt-5/stylesheet-reference.html`,
the property `overflow` doesn't exist, which leads to a warning message
in the console.
Morph