[FEATURE] ML client for pipeline setup and neural search

[mstephenson6]

Is your feature request related to a problem?

Yes, I am experimenting with the neural/semantic/k-NN search features in 2.13 described by Neural search tutorial and related docs. After going through it once the manual Dashboard way, I am writing client code to automate setting up /plugins/_ml/* support so I can have a repeatable cluster to tear down and spin up.

What solution would you like?

I would like to refine and submit this so others can re-use, in a similar fashion to the security plugin client. I want to gauge interest before I spend too much time cleaning/testing for PR.

This could also be a nice "sample", using the new client code in the same order as the neural tutorial, showing a semantic search for some movies in a small dataset.

[Jakob3xD]

We are always interested and happy for new contributions, especially for plugins. :+1: If you have any questions about this repo, you can reach out to me here or on the Opensearch slack.

[mstephenson6]

Thanks @Jakob3xD, I joined the Slack and I'll open a PR when I have a solid foundation to review.