Pyetm

Added additional example and updated mapping and regionalisation utility functions.

Fixes bug related to optional imports and adds example notebooks.

Refactoring of code to be more pre-commit compliant, with simplification for multitude of input parameters with 'get_input_parameters' function .

Replaced beta_engine argument with engine_url, etm_url and myc_url to allow to connect to custom ETM instances.

Beta server support for multi-year charts.