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

- Zentralisierte Nuget-Symbole.
 - Entfernte Projekte gelöscht.

DigitalData.Core.DTO/DigitalData.Core.DTO.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+	<TargetFrameworks>net7.0;net8.0</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <Description>This package provides Data Transfer Object (DTO) implementations and related utilities. It includes generic result handling, DTO extension methods, cookie consent settings management, and AutoMapper integration for robust object mapping, all adhering to Clean Architecture principles to ensure separation of concerns and maintainability.</Description>
@@ -12,13 +12,13 @@
     <Company>Digital Data GmbH</Company>
     <Product>DigitalData.Core.DTO</Product>
     <Copyright>Copyright 2024</Copyright>
-    <PackageIcon>icon.png</PackageIcon>
+    <PackageIcon>core_icon.png</PackageIcon>
     <RepositoryUrl>http://git.dd:3000/AppStd/WebCoreModules.git</RepositoryUrl>
     <PackageTags>digital data core dto clean architecture result pattern</PackageTags>
   </PropertyGroup>
 
   <ItemGroup>
-    <None Include="..\DigitalData.Core.Abstractions\Assets\icon.png">
+    <None Include="..\..\nuget-package-icons\core_icon.png">
       <Pack>True</Pack>
       <PackagePath>\</PackagePath>
     </None>