Add XML documentation for Org.Apache.Http.Impl.Cookie

The `Org.Apache.Http.Impl.Cookie` namespace contains **699** `To be added` placeholders in source XML documentation (excluding `docs\xml\index.xml`).

```powershell
rg -n -i --glob 'Org.Apache.Http.Impl.Cookie/**' --glob 'ns-Org.Apache.Http.Impl.Cookie.xml' 'to be added' docs\xml
```