Chore: Hinzufügen des .net 8-Frameworks zu allen .net-Projekten.

- Zentralisierte Nuget-Symbole.
 - Entfernte Projekte gelöscht.

DigitalData.Core.API/DigitalData.Core.API.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFrameworks>net7.0;net8.0</TargetFrameworks>
 	<IsPackable>true</IsPackable>
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
@@ -15,9 +15,16 @@
     <Copyright>Copyright 2024</Copyright>
     <RepositoryUrl>http://git.dd:3000/AppStd/WebCoreModules.git</RepositoryUrl>
     <PackageTags>digital data core api</PackageTags>
-    <PackageIcon>Assets\icon.png</PackageIcon>
+    <PackageIcon>core_icon.png</PackageIcon>
   </PropertyGroup>
 
+  <ItemGroup>
+    <None Include="..\..\nuget-package-icons\core_icon.png">
+      <Pack>True</Pack>
+      <PackagePath>\</PackagePath>
+    </None>
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Logging" Version="7.0.0" />
   </ItemGroup>