Add multi-targeting support for net7.0 and net8.0

Updated the project to support both net7.0 and net8.0 frameworks.
Modified `<TargetFramework>` to `<TargetFrameworks>` and added
conditional `<ItemGroup>` entries for dependencies and project
references specific to each framework. Updated package versions
(e.g., Microsoft.Extensions.DependencyInjection to 9.0.6) and
introduced new dependencies for net8.0, including
Microsoft.EntityFrameworkCore 8.0.17. Added a `<Compile Remove>`
directive for net7.0 to exclude Crypt-related files. Ensured
compatibility and maintained backward support for net7.0.

EnvelopeGenerator.Tests/EnvelopeGenerator.Tests.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>
 
@@ -17,7 +17,7 @@
     </Content>
   </ItemGroup>
 
-  <ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'net7.0'">
     <PackageReference Include="Bogus" Version="35.6.3" />
     <PackageReference Include="coverlet.collector" Version="6.0.0" />
     <PackageReference Include="DigitalData.Core.Abstraction.Application" Version="1.6.0" />
@@ -28,21 +28,60 @@
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="7.0.20" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="7.0.20" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="7.0.20" />
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="9.0.5" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="9.0.6" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="9.0.6" />
     <PackageReference Include="Microsoft.Identity.Client" Version="4.82.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
     <PackageReference Include="NUnit" Version="3.14.0" />
     <PackageReference Include="NUnit.Analyzers" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
-	<PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="9.0.5" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.12" />
-	<PackageReference Include="SixLabors.ImageSharp" Version="3.1.12" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
+    <PackageReference Include="Bogus" Version="35.6.3" />
+    <PackageReference Include="coverlet.collector" Version="6.0.0" />
+    <PackageReference Include="DigitalData.Core.Abstraction.Application" Version="1.6.0" />
+    <PackageReference Include="DigitalData.Core.Abstractions" Version="4.3.0" />
+    <PackageReference Include="DigitalData.Core.API" Version="2.2.1" />
+    <PackageReference Include="DigitalData.Core.Application" Version="3.4.0" />
+    <PackageReference Include="HtmlSanitizer" Version="9.0.892" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.17" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="8.0.17" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="8.0.17" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="8.0.17">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.17" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="9.0.6" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="9.0.6" />
+    <PackageReference Include="Microsoft.Identity.Client" Version="4.82.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+    <PackageReference Include="NUnit" Version="3.14.0" />
+    <PackageReference Include="NUnit.Analyzers" Version="3.9.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.12" />
+  </ItemGroup>
+	
   <ItemGroup>
     <ProjectReference Include="..\EnvelopeGenerator.Application\EnvelopeGenerator.Application.csproj" />
     <ProjectReference Include="..\EnvelopeGenerator.Infrastructure\EnvelopeGenerator.Infrastructure.csproj" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
+    <ProjectReference Include="..\EnvelopeGenerator.Infrastructure.Crypt\EnvelopeGenerator.Infrastructure.Crypt.csproj" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)' == 'net7.0'">
+    <Compile Remove="Application\Crypt\**\*.cs" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
+    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="9.0.6" />
+    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="9.0.6" />
+  </ItemGroup>
+
   <ItemGroup>
     <Using Include="NUnit.Framework" />
   </ItemGroup>