TODO: Cleanup of "dead code"

[BanjoFox]

Using VS Code and the rust-analyzer extension there are numerous "dead code", and "unused import" warnings being detected. Resolving these will not only help to implement functionality, but will also go a long way towards cleaning up the visual clutter when running tests and builds.

There may be instances, such as 'id' and 'csrf', where implementing a "TODO" function would be acceptable for the interim. On the other hand there are still numerous uses of e when it comes to error handling which should be implemented sooner than later.