Implement Pandas Curve Object

[patrick-reinhard]

This is a very large PR. The goal is to replace the Curve object (subclassed np.array) with a base class that is composed of a pd.DataFrame() object to hold the curve data. This will set-up welly to be able handle categorical and multi-dimensional curve data. It will also remove the necessity to handle a separate curve basis since we can leverage the pd.DataFrame.Index.

• Reading/writing, plotting and quality logic is moved out to respectively las.py, plot.py and quality.py. Added wrapper methods to classes.
• Replaced Curve object
• Adapted interfaces of functions & methods for new Curve objects
• Added Github Actions workflows for testing and publishing to PyPi
• Added tests

More details on this refactor effort and the HLD can be found in this issue.