Change to .net standard 2.0

Update EF and other dependencies to 3.1.4, add langversion 8.0, fix csvhelper usage, remove only non useable attribute

Author: KuraiAndras

ASPNETDemo/ASPNETDemo.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.2" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.4" />
   </ItemGroup>
 
   <ItemGroup>

Example/Example.csproj

@@ -6,8 +6,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.2" />
-    <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="3.0.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.4" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="3.1.4" />
   </ItemGroup>
 
   <ItemGroup>

FileContextCore/Check.cs

@@ -97,7 +97,7 @@ public static IReadOnlyList<T> HasNoNulls<T>(IReadOnlyList<T> value, [InvokerPar
         }
 
         [Conditional("DEBUG")]
-        public static void DebugAssert([System.Diagnostics.CodeAnalysis.DoesNotReturnIf(false)] bool condition, string message)
+        public static void DebugAssert(bool condition, string message)
         {
             if (!condition)
             {

FileContextCore/FileContextCore.csproj

@@ -1,7 +1,8 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <LangVersion>8.0</LangVersion>
     <SignAssembly Condition="'$(OS)' == 'Windows_NT'">true</SignAssembly>
     <AssemblyOriginatorKeyFile>FileContextCoreCert.snk</AssemblyOriginatorKeyFile>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
@@ -25,11 +26,11 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="CsvHelper" Version="12.1.3" />
-    <PackageReference Include="EPPlus" Version="4.5.3.2" />
-    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.2" />
-    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="3.0.0" />
-    <PackageReference Include="Newtonsoft.Json" Version="12.0.2" />
+    <PackageReference Include="CsvHelper" Version="15.0.5" />
+    <PackageReference Include="EPPlus" Version="5.1.2" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.4" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="3.1.4" />
+    <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
     <PackageReference Include="Newtonsoft.Json.Bson" Version="1.0.2" />
     <PackageReference Include="System.Xml.XmlSerializer" Version="4.3.0" />
   </ItemGroup>

FileContextCore/Serializer/CSVSerializer.cs

@@ -7,7 +7,7 @@
 using System.Text;
 using FileContextCore.Infrastructure.Internal;
 using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.ChangeTracking.Internal;
+using System.Globalization;
 
 namespace FileContextCore.Serializer
 {
@@ -34,7 +34,7 @@ public Dictionary<TKey, object[]> Deserialize<TKey>(string list, Dictionary<TKey
             }
 
             TextReader tr = new StringReader(list);
-            CsvReader reader = new CsvReader(tr);
+            CsvReader reader = new CsvReader(tr, CultureInfo.CurrentCulture);
 
             reader.Read();
             reader.ReadHeader();
@@ -61,7 +61,7 @@ public Dictionary<TKey, object[]> Deserialize<TKey>(string list, Dictionary<TKey
         public string Serialize<TKey>(Dictionary<TKey, object[]> list)
         {
             StringWriter sw = new StringWriter();
-            CsvWriter writer = new CsvWriter(sw);
+            CsvWriter writer = new CsvWriter(sw, CultureInfo.CurrentCulture);
 
             for (int i = 0; i < _propertyKeys.Length; i++)
             {