Density: Add pound abbreviations (#1506)

Fixes #1505

Introduces the missing `lbm` abbreviation for pounds in composed units
of measurement.

Author: hailstorm75

Common/UnitDefinitions/Density.json

@@ -76,7 +76,7 @@
       "Localization": [
         {
           "Culture": "en-US",
-          "Abbreviations": [ "lb/in³" ],
+          "Abbreviations": [ "lb/in³", "lbm/in³" ],
           "AbbreviationsForPrefixes": { "Kilo": "kip/in³" }
         }
       ]
@@ -94,7 +94,7 @@
       "Localization": [
         {
           "Culture": "en-US",
-          "Abbreviations": [ "lb/ft³" ],
+          "Abbreviations": [ "lb/ft³", "lbm/ft³" ],
           "AbbreviationsForPrefixes": { "Kilo": "kip/ft³" }
         }
       ]
@@ -113,7 +113,7 @@
       "Localization": [
         {
           "Culture": "en-US",
-          "Abbreviations": [ "lb/yd³" ],
+          "Abbreviations": [ "lb/yd³", "lbm/yd³" ],
           "AbbreviationsForPrefixes": { "Kilo": "kip/yd³" }
         }
       ]
@@ -337,7 +337,7 @@
       "Localization": [
         {
           "Culture": "en-US",
-          "Abbreviations": [ "lb/m³" ]
+          "Abbreviations": [ "lb/m³", "lbm/m³" ]
         }
       ]
     },
@@ -353,7 +353,7 @@
       "Localization": [
         {
           "Culture": "en-US",
-          "Abbreviations": [ "lb/cm³" ]
+          "Abbreviations": [ "lb/cm³", "lbm/cm³" ]
         }
       ]
     },
@@ -369,7 +369,7 @@
       "Localization": [
         {
           "Culture": "en-US",
-          "Abbreviations": [ "lb/mm³" ]
+          "Abbreviations": [ "lb/mm³", "lbm/mm³" ]
         }
       ]
     },

UnitsNet.Tests/GeneratedCode/TestsBase/DensityTestsBase.g.cs

@@ -36,12 +36,12 @@ NanogramsPerMilliliter=ng/ml
 PicogramsPerDeciLiter=pg/dl
 PicogramsPerLiter=pg/L
 PicogramsPerMilliliter=pg/ml
-PoundsPerCubicCentimeter=lb/cm³
-PoundsPerCubicFoot=lb/ft³
-PoundsPerCubicInch=lb/in³
-PoundsPerCubicMeter=lb/m³
-PoundsPerCubicMillimeter=lb/mm³
-PoundsPerCubicYard=lb/yd³
+PoundsPerCubicCentimeter=lb/cm³,lbm/cm³
+PoundsPerCubicFoot=lb/ft³,lbm/ft³
+PoundsPerCubicInch=lb/in³,lbm/in³
+PoundsPerCubicMeter=lb/m³,lbm/m³
+PoundsPerCubicMillimeter=lb/mm³,lbm/mm³
+PoundsPerCubicYard=lb/yd³,lbm/yd³
 PoundsPerImperialGallon=ppg (imp.)
 PoundsPerUSGallon=ppg (U.S.)
 SlugsPerCubicCentimeter=slug/cm³