Improve TypeUuid's derive macro error messages

[tguichaoua]

Objective

• Better error message
• More idiomatic code

Solution

Refactorize TypeUuid macros to use syn::Result instead of panic.

Before/After error messages

Missing #[uuid] attribtue

Before

error: proc-macro derive panicked
 --> src\main.rs:1:10
  |
1 | #[derive(TypeUuid)]
  |          ^^^^^^^^
  |
  = help: message: No `#[uuid = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"` attribute found.

After

error: No `#[uuid = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"]` attribute found.
 --> src\main.rs:3:10
  |
3 | #[derive(TypeUuid)]
  |          ^^^^^^^^
  |
  = note: this error originates in the derive macro `TypeUuid` (in Nightly builds, run with -Z macro-backtrace for more info)

Malformed attribute

Before

error: proc-macro derive panicked
 --> src\main.rs:3:10
  |
3 | #[derive(TypeUuid)]
  |          ^^^^^^^^
  |
  = help: message: `uuid` attribute must take the form `#[uuid = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"`.

After

error: `uuid` attribute must take the form `#[uuid = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"]`.
 --> src\main.rs:4:1
  |
4 | #[uuid = 42]
  | ^^^^^^^^^^^^

UUID parse fail

Before

error: proc-macro derive panicked
 --> src\main.rs:3:10
  |
3 | #[derive(TypeUuid)]
  |          ^^^^^^^^
  |
  = help: message: Value specified to `#[uuid]` attribute is not a valid UUID.: Error(SimpleLength { len: 3 })

After

error: Invalid UUID: invalid length: expected length 32 for simple format, found 3
 --> src\main.rs:4:10
  |
4 | #[uuid = "000"]
  |          ^^^^^

With Error Lens

Before

After

---

Changelog

• #[derive(TypeUuid)] provide better error messages.

[james7132]

LGTM. It'd be nice to have a UX test (like bevy_ecs_compile_fail_tests) for TypeUuid, but I won't block on that.