feat：更新包统一LOGO

Author: wangpengxpy

Directory.Build.props

@@ -15,8 +15,13 @@
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <PackageLicenseExpression>PostgreSQL</PackageLicenseExpression>
     <PackageProjectUrl>https://github.com/dotnetcore/EntityFrameworkCore.GaussDB</PackageProjectUrl>
+    <PackageIcon>icon.png</PackageIcon>
   </PropertyGroup>
 
+  <ItemGroup>
+    <None Include="$(MSBuildThisFileDirectory)icon.png" Pack="true" PackagePath="" />
+  </ItemGroup>
+
   <ItemGroup>
     <Using Include="System.Diagnostics" />
     <Using Include="System.Linq.Expressions" />