arrow

GH-41654: [MATLAB] Add new `arrow.c.Schema` MATLAB class which wraps a C Data Interface format `ArrowSchema` C struct (#41674)

### Rationale for this change

Now that the MATLAB interface has support for `arrow.tabular.RecordBatch` and `arrow.array.Array`, we should add support for the [C Data Interface](https://arrow.apache.org/docs/format/CDataInterface.html) format.

The C Data Interface is based around two C struct definitions: (1) `ArrowArray` and (2) `ArrowSchema`.

Now that #41653 (add support for `arrow.c.Array`) has been addressed, we should add another new MATLAB class (e.g. `arrow.c.Schema`) which wraps the underlying `ArrowSchema` C struct.

Once we have added these two MATLAB classes, we can then add import and export functionality to share the Arrow memory between multiple language runtimes running in the same process.

This would help enable workflows like sharing Arrow data between the MATLAB Interface to Arrow and `pyarrow` running within the MATLAB process via the [MATLAB interface to Python](https://www.mathworks.com/help/matlab/call-python-libraries.html)).

### What changes are included in this PR?

1. Added a new C++ proxy class called `arrow::matlab::c::proxy::Schema` which wraps an `ArrowSchema` struct pointer. This class is registered as the proxy `arrow.c.proxy.Schema` in order to make it accessible to MATLAB.

2. Added a new MATLAB class called `arrow.c.Schema` that has an `arrow.c.proxy.Schema` instance. It has one public property named `Address`, which is a scalar `uint64`. This property is the memory address of the `ArrowSchema` struct pointer owned by `arrow.c.proxy.Schema`.

### Are these changes tested?

Yes.

1. Added a new test class called `test/arrow/c/tSchema.m`.
2. @ sgilmore10 and I created a prototype for importing and exporting arrow `Array`s via the C Data Interface format [here](https://github.com/mathworks/arrow/tree/arrow-array-address). We were able to share arrow `Array`s and `RecordBatch`s between `mlarrow` and `pyarrow`. Our plan now is to submit the necessary MATLAB code incrementally.

### Are there any user-facing changes?

Yes.

1. The `arrow.c.Schema` class is user-facing. However, it's only intended for "advanced" use-cases. In the future, we may add higher-level functionality on top of the C Data Interface so that users don't need to interact with it directly.

2. **NOTE**: On destruction, `arrow.c.proxy.Schema` will check to see if the `ArrowSchema` has already been consumed by an importer. If not, `arrow.c.proxy.Schema`'s destructor will call the release callback on the `ArrowSchema` to avoid memory leaks. To the best of our knowledge, this is similar to the how the [Arrow PyCapsule Interface](https://arrow.apache.org/docs/format/CDataInterface/PyCapsuleInterface.html) works.

### Future Directions

1. #41656
2. We should probably follow up with a PR to create shared infrastructure for `arrow.c.Array` and `arrow.c.Schema`, since they are almost identical in design and implementation.

### Notes

1. Thank you @ sgilmore10 for your help with this pull request!
* GitHub Issue: #41654

Authored-by: Kevin Gurney <kgurney@mathworks.com>
Signed-off-by: Kevin Gurney <kgurney@mathworks.com>