add copy_settings=true to url params

[genevera]

From issue #1378, fixes #1375

Proposed Changes

• adds params={"copy_settings": "true"} to self.client.indices.shrink call

[untergeek]

Sorry for the very late response. I've looked at what you've contributed, but it needs some work before it can be merged.

1. It forces copy_settings: true whether you want it that way or not (it's not a setting). I'd like to see it be optional, with the default being false since that preserves the current default behavior.
2. It appears that the params block is not allowed in API calls before 6.4.0, so you can't just send params='', you have to omit the argument params altogether. This could be accomplished with an if/else block right where the call is made.
3. No tests cases to validate these settings. I can help you to write tests, if you are interested.

If you're not interested, I will eventually add these myself, via a different PR.

I'm willing to help you through these

[genevera]

No worries! I'd be happy to fix this up myself. Thank you for the review!

[untergeek]

Please rebase against the current master. There have been quite a few changes since this PR was submitted.