[TS] Clear current root item on refresh in RecsManager.
[Zalil] Fixed service name.
[Overall] Install qt5 plugins to "plugins-qt5" on Linux.
[Core] Install LC core as "leechcraft-qt5" if using Qt5.
[Core] Search for plugins in "plugins-qt5" on Linux.
[Util] "-qt5" suffix for utility libs on Qt5.