TreatWarningsAsErrors doesn't work on diagnostics configured via category

[jnm2]

Version Used: 16.10.0

Diagnostics configured via category or for all analyzers remain as warnings even when TreatWarningsAsErrors is true. They should instead be shown as errors in the error list and during command-line builds just like they do when each diagnostic is individually configured by ID to be a warning.

We don't want to configure these as errors because we don't want them to show that way in the IDE or block inner loop building/testing. We don't want to configure each diagnostic individually as a warning because that's a lot of lines. But we also want TreatWarningsAsErrors to turn these into errors during CI builds to prevent clutter from building up in the error list.

class C
{
    void M() { }
}

root = true

[*.cs]
dotnet_analyzer_diagnostic.category-CodeQuality.severity = warning

# This doesn't work either
dotnet_analyzer_diagnostic.category.severity = warning

# Uncomment to see the warning start showing as an error in the Error List and in command line builds
# dotnet_diagnostic.IDE0051.severity = warning

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net5.0</TargetFramework>
    <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
  </PropertyGroup>

</Project>

[mavasani]

Duplicate of #55541

[mavasani]

#58460 has been created to fix the underlying issue.