[feature] Add is_write_index: true/false in _cat/aliases API

[LoadingZhang]

Describe the feature:
Cat API is more readable but dosn't display is_write_index field.
I hope is_write_index field can be added to cat alias api, this is more convenient in some situations.

[bizybot]

Hi @LoadingZhang,
Thanks very much for your interest in Elasticsearch.
The changes to add is_write_index column to cat.aliases has been done in #44772. Hope this is what you were requesting.
I am closing this feature request as it is addressed now. Thank you.