.NET 8 (#125)

* Change target framework

* File scoped namespaces

* Global usings

* Collection initializers

* Primary constructors

* Centralized package management

* Build props

* Tidy

* File NS in goto

* More primary constructors

* Tidy

* Upgrades

* Various tidy

* No `this`

Author: langsamu

Directory.Build.props

@@ -0,0 +1,13 @@
+<Project>
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Using Include="VDS.RDF"/>
+    <Using Alias="Linq" Include="System.Linq.Expressions"/>
+  </ItemGroup>
+
+</Project>

Directory.Packages.props

@@ -0,0 +1,16 @@
+<Project>
+  <PropertyGroup>
+    <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageVersion Include="dotNetRDF" Version="3.3.0" />
+    <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
+    <PackageVersion Include="StyleCop.Analyzers" Version="1.1.118" />
+    <PackageVersion Include="ExpressionTreeToolkit.Core" Version="0.4.0" />
+    <PackageVersion Include="FluentAssertions" Version="7.0.0" />
+    <PackageVersion Include="coverlet.collector" Version="6.0.2" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
+    <PackageVersion Include="MSTest.TestAdapter" Version="3.6.4" />
+    <PackageVersion Include="MSTest.TestFramework" Version="3.6.4" />
+  </ItemGroup>
+</Project>