rest deprecation warnings

[paperdave]

i ran the auto generator for the routes file and i noticed

discord changed a route name. for us that is a breaking change.

i committed this instead.

this issue is for

• printing out the deprecation warning
• generator fixes
  • output from a newly created file deprecated-routes.json
  • detect changes in route names and update files correctly.
  • mechanism for us to reset the deprecated route list for major updates, which we can put out every few months if these changes continue happening.

it's honestly likely this is just overcomplicating a one-off rename, but it's a fun idea.