Batch trust regions implementation of TURBO

[khurram-ghani]

Related issue(s)/PRs: None

Summary

This PR adds a TURBO implementation based on the new batch-trust-region classes and replaces the original TURBO implementation.

The entry point filter_datasets in acquisition rules from the earlier local-models PR is called after acquisition and observation of new query-points, but before model training. Trust region algorithms do not update their regions in acquire anymore, instead the update is now in this new method. This enables the behaviour of the new TURBOBox class to match the previous TURBO implementation.

Existing notebook, unit tests and integration tests have been updated to use the new classes. The trust_region notebook shows how local models can be used with TURBOBox.

Fully backwards compatible: no

We have agreed that we don't need backwards compatibility.

Previously, a TURBO rule was created like this:

rule = TURBO(search_space)

This will need to be replaced with the following:

rule = BatchTrustRegionBox(TURBOBox(search_space))

PR checklist

• The quality checks are all passing
• The bug case / new feature is covered by tests
• Any new features are well-documented (in docstrings or notebooks)

[uri-granta]

(still looking but a few initial comments as I might not get a chance to get back to this before tomorrow)

[uri-granta]

(A few more comments...)