Merge 8.0.7 branch into main

[vladimir-litvinchik]

✨ PR Overview

This PR adds support for PathBase for the self-hosted API and adds READMEs to NuGet packages.

🛠️ Changes

1️⃣ Add Support for PathBase to Self-Hosted API

This issue was reported by one of our users in the Free Support Forum.
The PathBase value was being ignored during the stage when the API endpoint was generated.

For example, when running the app at a specific path—set during app composition in Program.cs:

var builder = WebApplication.CreateBuilder(args);

builder.Services
    .AddControllers()
    .AddGroupDocsViewerSelfHostApi();

var app = builder.Build();

app.UsePathBase("/TenantA");

app
    .UseRouting()
    .UseEndpoints(endpoints =>
    {
        endpoints.MapGroupDocsViewerApi();
    });

app.Run();

The API endpoint was not properly generated because the PathBase value (in this example, /TenantA) was ignored.
This issue has been fixed, and now PathBase is correctly taken into account when specified.

---

2️⃣ Add README to NuGet Packages

README files are now included in each NuGet package, and will appear on the package's page on NuGet.org.