Charts: indexed data property is confusing.

[FabienLelaquais]

🔍 What went wrong?

The fact that data is now (as of 4.2) index makes the API a bit confusing.
I would recommand that indexes for traces are used exactly the same manner, whether or not data is an array of datasets (used for independent, multi-trace charts) or used as an indexed property:

If

dataset1 = ...
dataset2 = ...
dataset = [dataset1, dataset2]

then
<|{dataset}|chart|...|> must be equivalent to <|{dataset1}|chart|data[1]=dataset2|...|>.

📦 Taipy Version

4.2

📋 Additional Context (Optional)

📜 Code of Conduct

• I have checked the existing issues to avoid duplicates.
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✅ Acceptance Criteria

• A reproducible unit test is added.
• Code coverage is at least 90%.
• The bug reporter validated the fix.
• Relevant documentation updates or an issue created in

[MohamedSharfan]

i would like to work on this issue