Most places use "khelpcenter" instead of "Help" to refer to the
appliction, the string "org.kde.Help" is only ever used for the
desktop file.
Also does KDBusService register on D-Bus based on the set application name,
thus org.kde.khelpcenter, not org.kde.Help, which cannot be easily adapted.

There are currently two known consumers which try to find khelpcenter
using KService::serviceByDesktopName("org.kde.help"), though seems
that broke recently due to KService becoming case-sensitive. As both
consumers (KGpg, Konqueror) are part of KDE Gear, they can be adapted
in sync and fixed to directly use the new name.