v1.0.0 - Cross-Validation improved!

[1.0.0] - 2024-07-03

Note: This is a major version bump, because we have quite substantial breaking changes. The 1.0 should not signal that we
are now feature complete. Though the core APIs have been mostly stable for quite some time now.

BREAKING CHANGE

• Instead of the (annoying) mock_label and group_label arguments, all functions that take a cv-splitter as input,
  can now take an instance of the new DatasetSplitter class, which elegantly handles grouping and stratification and
  also removes the need of forwarding the mock_label and group_label arguments to the underlying optimizer.
  The use of the mock_label and group_label arguments has been removed without depreciation.
  (#114)
• All classes and methods that "grid-search" or "cross-validate" like output (GridSearch, GridSearchCv, cross_validate, validate)
  have updated names for all their output attributes.
  In most cases the output naming has switched from a single underscore to a double underscore to separate the different
  parts of the output name to make it easier to programmatically access the output.
  (#117)