Add support for if_seq_no and if_primary_no

[jonatak]

Hello,

the official elasticsearch library offers the possibility to use if_seq_no and if_seq_no parameters:

https://elasticsearch-py.readthedocs.io/en/master/api.html#elasticsearch.Elasticsearch.index

I think it will be nice to update this library to support those parameters for index, delete, and update operation.

Thanks!

[vrcmarcos]

Hi @jonatak , ty for your comment! Do you mind to send a PR with this improvement?