Feature request: extend `merge_update` into BoxLists

[brynpickering]

Current

If I have these two BoxDicts:

In [1]: from box import Box
   ...: dict1 = Box({'data': [{'foo': 1, 'foobar': 20}, {'bar': 2}] }, box_dots=True)
   ...: dict2 = Box({'data': [{'foo': 1, 'baz': 10}] }, box_dots=True)
   ...: print(dict1.keys(dotted=True))
   ...: print(dict2.keys(dotted=True))
['data[0].foo', 'data[0].foobar', 'data[1].bar']
['data[0].baz', 'data[0].foo']

Then, if I use merge_update I get:

In [2]: dict1 + dict2
Out[2]: Box({'data': [{'foo': 1, 'baz': 10}]})

Expected behaviour

When merging the two datasets, it would be great if Box entered each list element and updated the dictionary:

In [1]: dict1 + dict2
Out[1]: Box({'data': [{'foo': 1, 'foobar': 20, 'baz': 10}, {'bar': 2}]})

Since the BoxDict has a pseudo-key for elements of the lists (e.g., 'data[0].foo') it feels like it should be possible.

Versions

python: 3.11
box: 7.1.1