Implement ApiErrorId with Uuid

[coord-e]

ApiErrorId is just a newtype of String.

misskey-rs/misskey-core/src/model.rs

Line 13 in 273c28a

pub struct ApiErrorId(pub String);

However, it seems that Misskey's error ID is actually a UUID.
Implementing ApiErrorID with Uuid has a big advantage, especially in terms of the ability to create constants.
It would be very useful to have known error IDs as constants.

Unresolved questions

• Are all Misskey's error IDs UUID?
• Where to implement error ID constants?