system: some refactoring

There's no need to move a temporary which is already an rvalue

Clean-up some redundant attributes and function in settings.
Make sure C types are proxied to fixed-sized ones, not the other way around.

Clean-up webprint implementation
- use typed duration for the backlog
- don't duplicate members and types for config, just re-use the struct as-is
- don't go over-the-top with const members, just proxy through a method

code/espurna/button.cpp

@@ -1144,7 +1144,7 @@ BasePinPtr _buttonGpioPin(size_t index, ButtonProvider provider) {
             break;
         }
 
-        result = std::move(base->pin(pin));
+        result = base->pin(pin);
 #endif
         break;
     }