Add Static Code Analysis

[danielmackay]

Add the following to Directory.Build.props

<Project>
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>

    <!-- Configure code analysis. -->
    <AnalysisLevel>latest</AnalysisLevel>
    <AnalysisMode>All</AnalysisMode>
    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
    <CodeAnalysisTreatWarningsAsErrors>false</CodeAnalysisTreatWarningsAsErrors>
    <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
  </PropertyGroup>
</Project>

Source: https://www.milanjovanovic.tech/blog/improving-code-quality-in-csharp-with-static-code-analysis

Consider only promoting warnings to errors in Release builds