feat: Enhance Pipeline.draw() to show image directly in Jupyter notebook

[silvanocerza]

Related Issues

• fixes When calling Pipeline.draw() in a notebook cell we should display the image directly #6802

Proposed Changes:

Change Pipeline.draw() to embed image if run in Jupyter notebook.
Now it can also be run without passing a path.
A path must still be provided if not running in a notebook, we raise a ValueError if missing.

How it appears on a Jupyter notebook ran in VS Code.

How did you test it?

I added some new unit tests and adapted the existing ones. I also tested it manually on a local Jupyter notebook.

Notes for the reviewer

In this PR I also changed the Pipeline.draw() API to remove the choice of a rendering engine and always use mermaid.
Rendering with graphviz has been completely removed.

I also restructured a bit the draw package to avoid annoying repetitions in import paths.

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test:.
• I documented my code
• I ran pre-commit hooks and fixed any issue

[coveralls]

Pull Request Test Coverage Report for Build 7843416947

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 21 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.4%) to 88.577%

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Files with Coverage Reduction	New Missed Lines	%
core/pipeline/pipeline.py	21	92.66%

Totals
Change from base Build 7829729731:	0.4%
Covered Lines:	4769
Relevant Lines:	5384

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💛 - Coveralls

[ZanSara]

I have a doubt about the API, the rest looks good

[ZanSara]

✔️