Update Robots Handler to support CMS 13

[GeekInTheNorth]

Update the robots handler add-on as follows:

• Compile for .NET 10
• Align with Optimizely CMS 13
  • Sites are replaced with applications
• Update main project to use a nullable context
• Remove warnings from moving from CMS 12 to CMS 13 and .NET 6 to .NET 10

Tasks:

• Update server side code
• Update react components to use application ids and names instead of sites
• End to End Developer testing
• Alpha Testing