"apt" is a wrapper for "apt-get" that is "better suited for
interactive usage", but really only adds overhead, and GitHub actions
are non-interactive by design.
Updated CMake toolchains: improved library search (link phase).
Updated gitignore to add KDevelop files.
Fixed unused parameters, now using them as fault check.
Added include guards to some headers.
Moved ISWHITESPACE from a macro to a templated function.
Fixed more missing virtual/override specifiers.
Moved from header to .cpp file some CClient methods.
Fixed: CItem::DupeCopy virtual method had a different signature from CObjBase::DupeCopy.
