Random C++ code style improvements
libdiscover: Random C++ code style improvements
ResourcesModel: Port isExtended from manual loop to std::any_of
Side-effect: with not a single backend present, the default return value will now be false instead of true. But realistically we don't care, as without backends there'd be no resources or IDs anyway.
UpdateModel: Demote backend setter from public slot to a regular method
UpdateModel: Fix up connections
- Disconnect only what's been explicitly connected, not nullptr aka "everything".
- Check new value against null before attempting to connect it.
Edited by ivan tkachenko