Read License information from configuration if present.

[KevinJump]

Currently licence information is read from the licence file in /umbraco/licenses - this does mean your licence will need to be stored on your site (or you would have to do some complicated replacement stuff on deployment).

the request to make it possible to store in the DB is in this issue: https://github.com/KevinJump/uSync/issues/315

As a solution - when reading the licence information - we will first look in the config.

"uSync" : {
  "Complete": {
      "License": {
        "Key": "LICENSE-KEY",
        "Domains": "LICENSE-DOMAIN"
      }
  }
}

• if the values are present in the config will will not attempt to load them from the file
• also if the values are in the config, clicking save in the UI will not save any information back to disk

by doing this the values can be stored in any of the configuration sources configured for a site (e.g appsettings.json, environmental variables, azure key vault etc).

[KevinJump]

code ready + tested