feat: LocoOptionExt: Helper methods to convert Option<T> into loco_rs::Result<T>

[dsgallups]

Objective

This PR adds new methods onto Option<T> to convert the None branch into an Error.

A common pattern I've found using loco is handling errors for model results when I need a specific model from sea_orm. For example, you usually have to do this in some controller:

let my_model = my_models::Entity::find_by_id(model_id)
  .await?
  .ok_or(Error::NotFound)?;

This is easy enough for converting into not found, but what if you'd like to do something else, like a custom error?

let my_model = my_models::Entity::find_by_id(model_id)
  .await?
  .ok_or(Error::CustomError(
      StatusCode::IM_A_TEAPOT,
      ErrorDetail::new("foo", "barbazqux")
  ));

After a while, this can get a big annoying to type everywhere. This PR adds new methods onto Option<T> to return errors with less syntax:

let my_model = my_models::Entity::find_by_id(model_id)
  .await?
  .status(
    StatusCode::IM_A_TEAPOT,
    "foo",
    "barbazqux"
  )?;

Further examples

LocoOptionExt::status

let optional_foo: Option<i32> = None;
let result: Result<i32> = optional_foo
    .status(StatusCode::BAD_REQUEST, "Missing number", "Maybe don't set optional_foo to None");

let Err(Error::CustomError(status, error_detail)) = result else {
    unreachable!();
};

assert_eq!(status, StatusCode::BAD_REQUEST);
assert_eq!(error_detail.error, Some("Missing number".to_string()));
assert_eq!(error_detail.description, Some("Maybe don't set optional_foo to None".to_string()));

LocoOptionExt::msg

let optional_foo: Option<i32> = None;
let result: Result<i32> = optional_foo
    .msg("Where'd my number go?");
let Err(Error::Message(msg)) = result else {
    unreachable!();
};
assert_eq!(msg, "Where'd my number go?".to_string())

LocoOptionExt::dbg()

let optional_foo: Option<i32> = None;
let result: Result<i32> = optional_foo.dbg();
let Err(Error::Message(msg)) = result else {
    unreachable!();
};

assert!(msg, "Found None::<i32> at src/errors.rs:7:40".to_string());

[dsgallups]

Note: in order to not expose the dbg callsite and type information in release builds, I could wrap this information in an #[cfg(profile = "dev")] block