Modernize NuGet dependencies and migrate to PackageReference (#823)

* Add .vscode to .gitignore

* Update copyright year

* Update Newtonsoft.Json package to version 13.0.4

* Migrate NuGet to PackageReference

* Replace vocaluxe.dependencies.sqlite with Microsoft.Data.Sqlite

* Update Serilog package references to latest versions

* Fix typo

Tests/Tests.csproj

@@ -1,7 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\NUnit3TestAdapter.3.10.0\build\net35\NUnit3TestAdapter.props" Condition="Exists('..\packages\NUnit3TestAdapter.3.10.0\build\net35\NUnit3TestAdapter.props')" />
-  <Import Project="..\packages\NUnit.3.10.1\build\NUnit.props" Condition="Exists('..\packages\NUnit.3.10.1\build\NUnit.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -56,13 +54,13 @@
     <PlatformTarget>x64</PlatformTarget>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="nunit.framework, Version=3.10.1.0, Culture=neutral, PublicKeyToken=2638cd05610744eb, processorArchitecture=MSIL">
-      <HintPath>..\packages\NUnit.3.10.1\lib\net45\nunit.framework.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
     <Reference Include="System" />
     <Reference Include="System.Xml" />
   </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="NUnit" Version="3.10.1" />
+    <PackageReference Include="NUnit3TestAdapter" Version="3.10.0" PrivateAssets="all" />
+  </ItemGroup>
   <ItemGroup>
     <Compile Include="PartyModeChallenge\CPartyModeChallangeTest.cs" />
     <Content Include="VocaluxeLib\Log\CLogTest.tt">
@@ -80,11 +78,6 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="VocaluxeLib\XML\CXmlSerializerTest.cs" />
   </ItemGroup>
-  <ItemGroup>
-    <None Include="packages.config">
-      <SubType>Designer</SubType>
-    </None>
-  </ItemGroup>
   <ItemGroup>
     <Service Include="{508349B6-6B84-4DF5-91F0-309BEEBAD82D}" />
     <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
@@ -113,13 +106,6 @@
     <Content Include="VocaluxeLib\XML\TestFiles\SThemeScreen.xml" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
-    <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
-    </PropertyGroup>
-    <Error Condition="!Exists('..\packages\NUnit.3.10.1\build\NUnit.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\NUnit.3.10.1\build\NUnit.props'))" />
-    <Error Condition="!Exists('..\packages\NUnit3TestAdapter.3.10.0\build\net35\NUnit3TestAdapter.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\NUnit3TestAdapter.3.10.0\build\net35\NUnit3TestAdapter.props'))" />
-  </Target>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
   <Target Name="BeforeBuild">

Tests/packages.config

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<packages>
-  <package id="NUnit" version="3.10.1" targetFramework="net47" />
-  <package id="NUnit3TestAdapter" version="3.10.0" targetFramework="net47" />
-</packages>