* Adds tests for Rust single file mode
All existing tests only compile Rust code using --rust-module-root-file.
* Adds standalone include tests for Rust
The imports for these tests have been moved to their own file, as the existing intergration_test.rs file hides compilation issues from code generation due to symbols brought into scope outside of the generated code (e.g. `extern crate alloc`).
* Declare alloc crate in every Rust namespace
When performing code generation within a single file, extern crate alloc needs to be delcared to bring alloc into scope within every inner namespace.
* Regenerates generated schemas
* Developers intro how to contribute
* Fix Rust code generation for Rust edition 2024
The errors look like:
```
warning[E0133]: call to unsafe function `fbs::flatbuffers::emplace_scalar` is unsafe and requires unsafe block
warning[E0133]: call to unsafe function `fbs::flatbuffers::follow_cast_ref` is unsafe and requires unsafe block
warning[E0133]: call to unsafe function `fbs::flatbuffers::Follow::follow` is unsafe and requires unsafe block
warning[E0133]: call to unsafe function `fbs::flatbuffers::read_scalar_at` is unsafe and requires unsafe block
warning[E0133]: call to unsafe function `fbs::flatbuffers::root_unchecked` is unsafe and requires unsafe block
warning[E0133]: call to unsafe function `fbs::flatbuffers::size_prefixed_root_unchecked` is unsafe and requires unsafe block
warning[E0133]: call to unsafe function `fbs::flatbuffers::Table::<'a>::new` is unsafe and requires unsafe block
warning[E0133]: call to unsafe function `std::slice::from_raw_parts` is unsafe and requires unsafe block
```
* Update goldens
Ran `goldens/generate_goldens.py`
* Regenerate code files
Ran `scripts/generate_code.py`
