Refactor and streamline codebase

- Removed `<Folder>` elements in `DocumentOperator.Domain.csproj`
  and replaced them with `<Compile Remove>`, `<EmbeddedResource Remove>`,
  and `<None Remove>` to exclude specific directories.
- Removed unused `using DocumentOperator.Domain.Exceptions;` directive.
- Simplified `Split` method syntax for delimiter specification.
- Updated `return` statements to use concise parameter syntax.
- Removed page number validation logic in `DevExpressSwissQrCodeProcessor`.
- Replaced default page scanning logic with modern range expression.
- Overall, improved code clarity, reduced redundancy, and modernized syntax.

DocumentOperator.Domain/DocumentOperator.Domain.csproj

@@ -7,8 +7,12 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Folder Include="Common\Results\" />
-    <Folder Include="Constants\" />
+    <Compile Remove="Common\Results\**" />
+    <Compile Remove="Constants\**" />
+    <EmbeddedResource Remove="Common\Results\**" />
+    <EmbeddedResource Remove="Constants\**" />
+    <None Remove="Common\Results\**" />
+    <None Remove="Constants\**" />
   </ItemGroup>
 
 </Project>