Add File Sink

[RubenCerna2079]

Add a file sink that will allow the information from the log to be written into the file. Additionally, a new file property will be added to the configuration file that will be under runtime and that can be enabled in order for the file to receive the logging information.

Configuration File with Sink

{
  "runtime": {
      ...
      "telemetry": {
          "application-insights": {
              "enabled": true,
              "connection-string": "@env('app-insights-connection-string')"
          }
      },
      "file": {
          "enabled": true,
          "path": "/logs/dab-log.txt",
          "rollingInterval": "Day",
          "retainedFileCountLimit": 7,
          "fileSizeLimitBytes": 10485760
       },
      ...
  }
}