Use built-in (and up-to-date) .NET Analyzers

Since all our projects target the `Microsoft.NET.Sdk` we can use
roslyn's built-in analyzers instead of the out-of-date package (we could
update that instead, but this is the modern method).

Author: andyleejordan

PowerShellEditorServices.Common.props

@@ -11,5 +11,8 @@
     <RepositoryType>git</RepositoryType>
     <RepositoryUrl>https://github.com/PowerShell/PowerShellEditorServices</RepositoryUrl>
     <DebugType>portable</DebugType>
+    <!-- See: https://docs.microsoft.com/en-us/dotnet/fundamentals/code-analysis/overview -->
+    <EnableNETAnalyzers>true</EnableNETAnalyzers>
+    <!-- TODO: Enable `EnforceCodeStyleInBuild` -->
   </PropertyGroup>
 </Project>

src/PowerShellEditorServices.Hosting/PowerShellEditorServices.Hosting.csproj

@@ -31,10 +31,6 @@
 
   <ItemGroup>
     <ProjectReference Include="..\PowerShellEditorServices\PowerShellEditorServices.csproj" PrivateAssets="all" />
-    <PackageReference Include="Microsoft.CodeAnalysis.FxCopAnalyzers" Version="3.3.2">
-      <PrivateAssets>all</PrivateAssets>
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-    </PackageReference>
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)'=='net461'">

src/PowerShellEditorServices/PowerShellEditorServices.csproj

@@ -1,5 +1,4 @@
 <Project Sdk="Microsoft.NET.Sdk">
-
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), PowerShellEditorServices.Common.props))\PowerShellEditorServices.Common.props" />
 
   <PropertyGroup>