[Base/Units] Change strings' description

Affect strings presented to the user on the combobox to select unit system.

- The symbol to represent angles on "degree" unit is '°'
- Change imperial velocity to "ft/s" to enforce the use of 's' symnbol as second

src/Base/UnitsApi.cpp

@@ -66,9 +66,9 @@ QString UnitsApi::getDescription(UnitSystem system)
 {
     switch (system) {
         case UnitSystem::SI1:
-            return tr("Standard (mm, kg, s, degree)");
+            return tr("Standard (mm, kg, s, °)");
         case UnitSystem::SI2:
-            return tr("MKS (m, kg, s, degree)");
+            return tr("MKS (m, kg, s, °)");
         case UnitSystem::Imperial1:
             return tr("US customary (in, lb)");
         case UnitSystem::ImperialDecimal:
@@ -80,7 +80,7 @@ QString UnitsApi::getDescription(UnitSystem system)
         case UnitSystem::MmMin:
             return tr("Metric small parts & CNC(mm, mm/min)");
         case UnitSystem::ImperialCivil:
-            return tr("Imperial for Civil Eng (ft, ft/sec)");
+            return tr("Imperial for Civil Eng (ft, ft/s)");
         case UnitSystem::FemMilliMeterNewton:
             return tr("FEM (mm, N, s)");
         case UnitSystem::MeterDecimal:

src/Base/UnitsSchema.h

@@ -42,7 +42,7 @@ enum class UnitSystem
     Centimeters = 4,     /** All lengths in centimeters, areas and volumes in square/cubic meters */
     ImperialBuilding = 5, /** All lengths in feet + inches + fractions */
     MmMin = 6, /** Lengths in mm, Speed in mm/min. Angle in degrees. Useful for small parts & CNC */
-    ImperialCivil = 7, /** Lengths in ft, Speed in ft/sec. Used in Civil Eng in North America */
+    ImperialCivil = 7,       /** Lengths in ft, Speed in ft/s. Used in Civil Eng in North America */
     FemMilliMeterNewton = 8, /** Lengths in mm, Mass in t, TimeSpan in s, thus force is in N */
     MeterDecimal = 9,        /** Lengths in metres always */
     NumUnitSystemTypes       // must be the last item!