Activate .NET code analysis

[Regenhardt]

Taken from the open BaGet PR loic-sharma#784

[FroggieFrog]

According to the build workflow, there is still one issue left:

[FroggieFrog]

Maybe you can integrate 2 more changes from PR #46 (then #46 is superfluous and can be closed)

1. in src/BaGetter.Core/Entities/Converters/StringArrayToJsonConverter.cs: line 14 v => (!string.IsNullOrEmpty(v)) ? JsonConvert.DeserializeObject<string[]>(v) : Array.Empty<string>())
2. in tests/BaGetter.Tests/HostIntegrationTests.cs: line 65 .CreateHostBuilder(Array.Empty<string>())

[seriouz]

@Regenhardt Can you merge?