Refactor vuecore library with an initial example for scatter plot

[sayalaruano]

This structure would enable the support of various backend engines and separate the validation, style, and building logic for the plots.

Here is a diagram of the proposed project structure:

vuecore/
├── __init__.py
├── constants.py         # Defines global enums and constants (e.g., plot types, engine types)
├── engines/             # Manages all plotting backends
│   ├── __init__.py      # Engine registry and loading logic
│   ├── plotly/             
│   │   ├── __init__.py  # Registers Plotly engine components
│   │   ├── saver.py     # Functions to save Plotly figures
│   │   ├── theming.py   # Applies styles and themes to Plotly figures
│   │   ├── scatter.py   # Generates plotly scatter plots from data and config
│   │   └── ... 
├── plots/               # User-facing API
│   ├── basic/       
│   │   ├── scatter.py   # Creates scatter plots using schemas and engines
│   │   └── ...
│   ├── .../        
├── schemas/             # Pydantic models for validating plot configurations
│   ├── basic/          
│   │   ├── scatter.py  
│   │   └── ...
├── utils/               # Helper functions shared across the project
│   ├── statistics.py           
│   ├── validation.py    # Custom validation logic beyond Pydantic 
└── ...
tests/
├── test_scatter.py      # Unit and integration tests for scatter plot generation
│   
docs/
├── api_examples/       # Plot examples
│   ├── scatter_plot.py           
│   ├── scatter_plot.py    
└── ...

Also, here is the workflow:

User Code
    │
    ▼
plots/basic/scatter.py             # "Create scatter plot"
    │
    │ Uses
    ├──► schemas/basic/scatter.py  # Pydantic validation
    │                        │
    │                        └──► utils/validation.py    # Custom validation
    │
    │ Uses
    ├──► constants.py                     # Access plot types, engine types, etc.
    │
    │ Selects engine:
    ▼
engines/plotly/scatter.py       # Generate Plotly scatter plot from data + config
    │
    │ Uses
    ├──► engines/plotly/theming.py        # Apply theming
    │
    │ Uses
    ├──► utils/statistics.py              # Support for transformations, etc
    │
    │ Uses
    ▼
engines/plotly/saver.py              # Save plot (e.g., as PNG/HTML/JSON)

[enryH]

This is a simple version of pandera. Let's discuss that tomorrow.

[enryH]

I would add a small api-example in docs/api-examples/scatter.ipynb to highlight it in the docs. Maybe the current small test case is enough?

[enryH]

I will need to see if it's easy to inspect the arguments of ScatterConfig in an interactive session. I will do this in a bit.

[enryH]

needs to be one indentation to the left I think