Deprecate rotation rates as single Float

[ty-porter]

With the new config updater, there's a chance to overwrite this value with schema defaults. This PR formally deprecates that functionality and provides an upgrade path to the full dict format.

Deprecates:

{
  "rotation": {
    "rates": 15.0
  }
}

Converts to:

{
  "rotation": {
    "rates": {
    "live": 15.0,
    "final": 15.0,
    "pregame": 15.0
    }
}