ResourcesModel: General clean up
General clean up
Includes two little optimizations:
- Don't emit backendsChanged() when no backends has been added.
- Use short-circuiting std::any_of for hasSecurityUpdates() aggregate.
Port timer from pointer to inline object
It saves us from a redundant allocation. Also give it a name, to make it easier to locate and debug with GammaRay if needed.