Update Report Server documentation with latest changes for msi installer

[PetiaVladova]

With 2024 Q2 MSI installer is extended with support for .NET (Core) flavor of the Report Server.

https://github.com/telerik/vsx/issues/933

In summary the changes are the following:

• The RS installer should bring the RS.NET app assets
• Installer UX
• The CUSTOMIZATION page of the installer should rename the current root level feature on Telerik Report Server on .NET Framework 4.6.2+that is turned ON by default
• The CUSTOMIZATION page of the installer should add another feature on the root level called Telerik Report Server on .NET 8, that is turned OFF by default
• If Upgrade is running each root option that is already installed should be turned on and disabled so that it cannot be removed, but if not already installed the user can add it. Effectively, when they upgrade they will be able to install the new flavor so that they have both side-by-side in order to test, adopt, and migrate to the new one
• Turning on the new option should deploy the new set of assets, set up a dedicated web app in IIS running on .NET 8, run the deployed Scheduled service (if it continues to be a separate svc app)