Feature/auto compress pickle study

[LGro]

• Move saving and loading to new blackboxopt.io submodule.
• Add lzma (de-)compression for study pickle serialization.
• Bump major version due to breaking changes.

[github-actions]

---------- coverage: platform linux, python 3.11.3-final-0 -----------
Name                                                     Stmts   Miss  Cover
----------------------------------------------------------------------------
blackboxopt/__init__.py                                      6      0   100%
blackboxopt/base.py                                         76      0   100%
blackboxopt/evaluation.py                                   58      4    93%
blackboxopt/io.py                                           36      0   100%
blackboxopt/optimization_loops/__init__.py                   0      0   100%
blackboxopt/optimization_loops/dask_distributed.py          69      5    93%
blackboxopt/optimization_loops/sequential.py                34      3    91%
blackboxopt/optimization_loops/testing.py                   31      0   100%
blackboxopt/optimization_loops/utils.py                     31      0   100%
blackboxopt/optimizers/__init__.py                           0      0   100%
blackboxopt/optimizers/bohb.py                              20      2    90%
blackboxopt/optimizers/botorch_base.py                     134     33    75%
blackboxopt/optimizers/botorch_utils.py                     56      1    98%
blackboxopt/optimizers/hyperband.py                         19      2    89%
blackboxopt/optimizers/random_search.py                     14      0   100%
blackboxopt/optimizers/space_filling.py                     15      2    87%
blackboxopt/optimizers/staged/__init__.py                    0      0   100%
blackboxopt/optimizers/staged/bohb.py                      184     29    84%
blackboxopt/optimizers/staged/configuration_sampler.py      15      0   100%
blackboxopt/optimizers/staged/hyperband.py                  13      0   100%
blackboxopt/optimizers/staged/iteration.py                  65      0   100%
blackboxopt/optimizers/staged/optimizer.py                  44      0   100%
blackboxopt/optimizers/staged/utils.py                      26      3    88%
blackboxopt/optimizers/testing.py                          162      4    98%
blackboxopt/utils.py                                        32      0   100%
blackboxopt/visualizations/__init__.py                       0      0   100%
blackboxopt/visualizations/utils.py                         88     19    78%
blackboxopt/visualizations/visualizer.py                   245     25    90%
----------------------------------------------------------------------------
TOTAL                                                     1473    132    91%

=========================== short test summary info ============================
FAILED tests/package_test.py::test_pyproject_toml_version_matches_dunder_version - AssertionError: assert '5.0.0' == '4.15.1'
  - 4.15.1
  + 5.0.0
============ 1 failed, 139 passed, 31 warnings in 62.45s (0:01:02) =============

[sfalkner]

Thanks @LGro for this prompt and clean implementation :)