Added mutation for multiple items

[olegkron]

Added a function which allows to modify multiple items at once using graphQL's mutation query.
The function takes a list of dictionaries with methods and any additional parameters the method requires.

This already saved me hours when working with large sets of data, as the only way to work with multiple items with this library was to call the update/create functions one by one, whereas now you're able to perform multiple operations at once.

Hope you find it as much of a lifesaver too!

items_data = [
    {
        "method": "create_item",
        "board_id": 1437462152,
        "group_id": "new_group",
        "item_name": "New Item",
        "column_values": {"status": "done"},
        "create_labels_if_missing": True
    },
    {
        "method": "change_multiple_column_values",
        "board_id": 1435323152,
        "item_id": 1345543264,
        "column_values": {"status": "done"},
        "create_labels_if_missing": True
    }
]

response = monday.items.mutate_multiple_items(items_data)

[olegkron]

Hi @chdastolfo, please let me know if there's time to review this pull request. Thanks!

[chdastolfo]

Thanks for your contribution! This looks good, but could you please add test(s) for this as well? It would be good, for example, to make sure this query looks right for various lengths of if the item_data array (length, 1, >1).

[chdastolfo]

🙏

[chdastolfo]

Would prefer item_data, and data as it is more grammatically correct than items_data and item_data. I think the function name makes it clear that the function acts on multiple items.

[chdastolfo]

Also! Please add this method to the docs in docs/README.rst

[danielcherrington]

@chdastolfo Being able to group mutations/queries is a really useful feature. Are there any plans for this PR to make it into a release?