Split dotnet and dotnetisolated builds

[pragnagopa]

InProc Dotnet6 image is still on 4.35.1 hostversion as it has base image

docker inspect mcr.microsoft.com/azure-functions/dotnet:4.35.1.2-dotnet6-appservice

"Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "ASPNETCORE_URLS=http://+:80",
                "DOTNET_RUNNING_IN_CONTAINER=true",
                "AzureWebJobsScriptRoot=/home/site/wwwroot",
                "HOME=/home",
                "FUNCTIONS_WORKER_RUNTIME=dotnet",
                "DOTNET_USE_POLLING_FILE_WATCHER=true",
                "HOST_VERSION=4.35.1",
                "ASPNETCORE_CONTENTROOT=/azure-functions-host"
            ],

This PR splits InProc and DotnetIsoalated builds as they will be on different host versions going forward