adjust toner levels to make more practical sense

lib/src/models/printer_status.dart

@@ -165,8 +165,8 @@ class PrinterStatus {
 
   Level _percentageToLevel(int percentage) {
     if (percentage >= 90) return Level.full;
-    if (percentage >= 25) return Level.mid;
-    if (percentage > 0) return Level.low;
+    if (percentage >= 30) return Level.mid;
+    if (percentage > 10) return Level.low;
     return Level.empty;
   }
 }

lib/src/printers/printers_bloc.dart

@@ -308,22 +308,22 @@ class PrintersBloc extends Bloc<PrintersEvent, PrintersState> {
             if (printer.status.tonerC > 100) {
               printer.status.tonerC = 100;
             } else if (printer.status.tonerC < 0) {
-              printer.status.tonerC = 0;
+              printer.status.tonerC = 10;
             }
             if (printer.status.tonerM > 100) {
               printer.status.tonerM = 100;
             } else if (printer.status.tonerM < 0) {
-              printer.status.tonerM = 0;
+              printer.status.tonerM = 10;
             }
             if (printer.status.tonerY > 100) {
               printer.status.tonerY = 100;
             } else if (printer.status.tonerY < 0) {
-              printer.status.tonerY = 0;
+              printer.status.tonerY = 10;
             }
             if (printer.status.tonerK > 100) {
               printer.status.tonerK = 100;
             } else if (printer.status.tonerK < 0) {
-              printer.status.tonerK = 0;
+              printer.status.tonerK = 10;
             }
 
             // catch paper levels under 0 to make calculations work properly