Nanite

- feat: allow to define ancillary parameters for models and use them
during fitting by default
- feat: `Indentation.get_initial_fit_parameters` now automatically
computes common and model-related ancillary parameters if no
initial parameters are present
- enh: allow to set the `model_key` in more functions of `Indentation`
- ref: use `idnt` to represent Indentation instances
- fix: preprocessing steps not stored in `Indentation.preprocessing`
- setup: bump afmformats from 0.4.1 to 0.5.0

- enh: update boundaries and default values for model parameters

- fix: FitProperties did not detect changes in "params_initial"

- setup: bump afmformats version from 0.3.0 to 0.4.1

- enh: skip computation of tip position if it is already in the
dataset and cannot be computed e.g. due to missing spring constant
- fix: typo in get_data_paths_enum
- setup: bump afmformats version from 0.2.0 to 0.3.0

- tests: np.asscalar is deprecated
- ref: migrate to afmformats (1)
- docs: minor improvements