[ML] Adding bulk create functionality to ModelRegistry (elastic#136569)

* Adding bulk storage of multiple models

* Adding tests

* Adding log for duplicate ids

* [CI] Auto commit changes from spotless

* Removing unused code

* Removing constructor

* Adding more tests

* Adding in logic to delete models when a failure occurs

* revert rename changes

* formatting

* Starting on feedback

* Improving tests

* Moving most tests to ModelRegistryIT

* [CI] Auto commit changes from spotless

* Fixing test

* Removing duplicate tests

* Handling empty list and duplicates

* Fixing empty delete

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Co-authored-by: elasticsearchmachine <[email protected]>

Author: 2 people