fix: stack with time axes

[archiewood]

Brief Information

This pull request is in the type of:

• bug fixing
• new feature
• others

Currently I believe time axes are "not supported" with stack as mentioned in docs, which would make this a new feature. But also this has been reported as a bug several times.

What does this PR do?

Supports using "stack" for time-based charts

Fixed issues

• [Bug] Stacked bars do not work on time x axis when data is not fully synchronized #20254
• Cannot stack bars on time x-axis #7937
• [Bug] Gaps between stacked bar chart data series #20096

Details

Before: What was the problem?

Using stack with time axes does work in many cases today.

But if you attempted to use stack with time axes, and the series are not in the same order, then the stacks will render incorrectly. The stacked series will use the index to determine the start position, not the time.

Reproduction

After: How does it behave after the fixing?

The stacks will look up the stack using the time value instead of the index

Document Info

One of the following should be checked.

• This PR doesn't relate to document changes
• The document should be updated later
• The document changes have been made in apache/echarts-doc#xxx

Misc

Security Checking

• This PR uses security-sensitive Web APIs.

ZRender Changes

• This PR depends on ZRender changes (ecomfe/zrender#xxx).

Related test cases or examples to use the new APIs

let option={
  "xAxis": {
    "type": "time"
  },
  "series": [
    {
      "name": "A",
      "type": "bar",
      "data": [
        ["2025-01-01",4],
        ["2025-02-01",8]
      ],
      "stack": "stack1"
    },
    {
      "name": "B",
      "type": "bar",
      "data": [
        ["2025-02-01",3],
        ["2025-01-01",9,]
      ],
      "stack": "stack1",
    }
  ],
  "yAxis": [
    {
      "type": "value"
    }
  ]
}

Merging options

• Please squash the commits into a single one when merging.

Other information

[echarts-bot]

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Document changes are required in this PR. Please also make a PR to apache/echarts-doc for document changes and update the issue id in the PR description. When the doc PR is merged, the maintainers will remove the PR: awaiting doc label.