arrow

ARROW-15389: [C++][Dev] Improve Array preview in GDB plugin

When printing a arrow::Array or arrow::ArrayData, try to print the array contents as well as its metadata.

This is implemented for all primitive and binary-like types.
Other types will only display the array metadata.

Example:
```
(gdb) p *heap_binary_array.get()
$23 = arrow::BinaryArray of length 3, offset 0, null count 1 = {[0] = null, [1] = "abcd", [2] = "\000\037\377"}
```

Closes #12315 from pitrou/ARROW-15389-gdb-array-preview

Authored-by: Antoine Pitrou <antoine@python.org>
Signed-off-by: David Li <li.davidm96@gmail.com>