Modelskill

* Fix pandas styler deprecation warning

- Altimetry API updates
- load time improvements, only import xarray when needed

* Add shapely as a dependency

* It is now possible to provide a track ModelResult as a pandas DataFrame

* DHI Altimetry data download from api
* Hit ratio metric
* Custom metric example
* Add more modelresults to existing comparer
* Better merging of comparers also if time period is overlapping
* Fix bug in TrackComparer

* ModelResult now supports NetCDF including multiple-file NetCDF data using xarray as backend
* An example can be seen here: https://nbviewer.jupyter.org/github/DHI/fmskill/blob/main/notebooks/NetCDF_ModelResult.ipynb
* ModelResult also supports xarray input
* Connector can now write a config file with information about filenames, items etc of ModelResults and Observations
* Connector can write config to dict or to yaml or xlsx files
* Connector can also read config files from both yaml and xlsx files