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GH-38015: [MATLAB] Add `arrow.buffer.Buffer` class to the MATLAB Interface (#38020)



### Rationale for this change

To unblock use cases that are not satisfied by the default Arrow -> MATLAB conversions (i.e. the `toMATLAB()` on `arrow.array.Array`), we would like expose the underlying Arrow data representation as a property on `arrow.array.Array`. One possible name for this property would be `DataLayout`, which would be an `arrow.array.DataLayout` object. Note, this class does not yet exist, so we would have to add it.

For example, the `DataLayout` property for temporal array types would return an object of the following class type: 

```matlab
classdef TemporalDataLayout < arrow.array.DataLayout
    properties
       Values % an arrow.array.Int32Array or an arrow.array.Int64Array
       Valid  % an arrow.buffer.Buffer 
    end
end
```

However, the `Valid` property on this class would need to be an `arrow.buffer.Buffer` object, which does not yet exist in the MATLAB interface.  Therefore, it would be helpful to first add the `arrow.buffer.Buffer` class before adding the `DataLayout` property/class hierarchy. It's worth mentioning that adding `arrow.buffer.Buffer` will open up additional advanced use cases in the future.

### What changes are included in this PR?

Added `arrow.buffer.Buffer` MATLAB class.

*Properties of `arrow.buffer.Buffer`*
 1. `NumBytes` - a  scalar `int64` value representing the size of the buffer in bytes. 

*Methods of `arrow.buffer.Buffer`*
1. `toMATLAB` - returns the data in the buffer as `Nx1` `uint8` vector, where `N` is the number of bytes.
2. `fromMATLAB(data)` - Static method that creates an `arrow.buffer.Buffer` from a numeric array. 

**Example:**
```matlab
>> dataIn = [1 2];
>> buffer = arrow.buffer.Buffer.fromMATLAB(dataIn)

buffer = 

  Buffer with properties:

    NumBytes: 16

>> dataOut = toMATLAB(buffer)

dataOut =

  16×1 uint8 column vector

     0
     0
     0
     0
     0
     0
   240
    63
     0
     0
     0
     0
     0
     0
     0
    64

% Reinterpret bit pattern as a double array 
>> toDouble = typecast(dataOut, "double")

toDouble =

     1
     2
```

### Are these changes tested?

Yes. Added a new test class called `tBuffer.m`

### Are there any user-facing changes?

Yes. Users can now create `arrow.buffer.Buffer` objects via the `fromMATLAB` static method. However, there's not much users can do with this object as of now. We implemented this class to facilitate adding `DataLayout` property to `arrow.array.Array`, as described in the **Rational for this change** section. 

* Closes: #38015

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