Use nameof when instantiating headless game hosts
Use nameof when instantiating headless game hosts

As a purely cosmetic code improvement, substitute string literals
in constructor calls of HeadlessGameHost in ImportBeatmapTest for nameof
operator usages.

NeoAdonis/osu,johnneijzen/osu,peppy/osu-new,UselessToucan/osu,johnneijzen/osu,smoogipooo/osu,2yangk23/osu,2yangk23/osu,NeoAdonis/osu,ppy/osu,NeoAdonis/osu,smoogipoo/osu,UselessToucan/osu,peppy/osu,UselessToucan/osu,smoogipoo/osu,EVAST9919/osu,ppy/osu,smoogipoo/osu,peppy/osu,EVAST9919/osu,peppy/osu,ppy/osu