Wip support for compressing/decompressing nucache documents on a per property basis. Option for compressing the properties in sql/nucache.db. Option for immediate/lazy decompression of properties. Mapping support for shorter property alias.

TODO: config file for property map
TODO:  HasValue and IsValue on propertyvalueconverterbase

src/Umbraco.Web/PublishedCache/NuCache/DataSource/AppSettingsNucachePropertyMapFactory.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Umbraco.Web.PublishedCache.NuCache.DataSource
+{
+    public class AppSettingsNucachePropertyMapFactory : INucachePropertyOptionsFactory
+    {
+        public NucachePropertyOptions GetNucachePropertyOptions()
+        {
+            NucachePropertyOptions options = new NucachePropertyOptions
+            {
+                PropertyMap = GetPropertyMap(),
+                LZ4CompressionLevel = K4os.Compression.LZ4.LZ4Level.L10_OPT,
+                MinimumCompressibleStringLength = null
+            };
+            return options;
+        }
+
+        public IReadOnlyDictionary<string, (NucachePropertyCompressionLevel compress, NucachePropertyDecompressionLevel decompressionLevel, string mappedAlias)> GetPropertyMap()
+        {
+            var propertyMap = new Dictionary<string, (NucachePropertyCompressionLevel compress, NucachePropertyDecompressionLevel decompressionLevel, string mappedAlias)>();
+            // TODO: Use xml/json/c# to define map
+            var propertyDictionarySerializerMap = ConfigurationManager.AppSettings["Umbraco.Web.PublishedCache.NuCache.PropertySerializationMap"];
+            if (!string.IsNullOrWhiteSpace(propertyDictionarySerializerMap))
+            {
+                //propertyAlias,CompressionLevel,DecompressionLevel,mappedAlias;
+                propertyDictionarySerializerMap.Split(';')
+                    .Select(x =>
+                    {
+                        var y = x.Split(',');
+                        (string alias, NucachePropertyCompressionLevel compressionLevel, NucachePropertyDecompressionLevel decompressionLevel, string mappedAlias) v = (y[0],
+                        (NucachePropertyCompressionLevel)System.Enum.Parse(typeof(NucachePropertyCompressionLevel), y[1]),
+                        (NucachePropertyDecompressionLevel)System.Enum.Parse(typeof(NucachePropertyDecompressionLevel), y[2]),
+                        y[3]
+                        );
+                        return v;
+                    })
+                    .ToList().ForEach(x => propertyMap.Add(x.alias, (x.compressionLevel, x.decompressionLevel, x.mappedAlias)));
+            }
+            return propertyMap;
+        }
+    }
+}