[Bug] `labelLayout.draggable` in series of type `graph` doesn't affect edge labels.

### Version

5.4.2

### Link to Minimal Reproduction

[Link](https://echarts.apache.org/examples/en/editor.html?code=LYTwwgFghgTgLgOgM4QPYHcAyqoBMCWAdgOYAUAlANwBQAJAsQKZykBKA8uwCoD6ACgEEuACQAEAalEByAPS4ocKDKhIkzGU1QyAqgGUBCAFZJUhKQBpRAMwCuhAMZx8p0aU0ApE4XKiA3tVFRRntoeCQEGEZifCQ4RhgAWSgAB1IpGyQLUQ8vKgDRVGSnFwBeP3zAzQAucsC60WAUmoAiDObzCrqYHGAauBgbRksAL1RUXoBmDvrApHwAG0ZCOBqrKHm1aZn7JbiYGoBtAFoAThOEE4B2SwnLhEuARgBdfIBfLdn4_EYkQ87A_wzOpwEDJRg1KTEGApCAWf51exjGAEQgKRi6ECxRi9UTNTTteGVRioACShFwjAAHjUAAwfGZIEDAABGqHmunww3BogedMJom6UBx_UG9PquGhxGIUGZiz6AyG_PmMsY8xqgKBdRQGHlov5gSsqBgjTgewhvgAAgcAExPV5wzV1ZKoObFQgQ1mm8ZSfnvJUq-aYKAgVA2FjJWBCpA-DWOyJwGwwQi1R11amiCPQ4DhSKOBCUsWakA1TNRiLBRAgCQ8gCshaBEqgUplctEIsVqdEr199aCuCYGJZbMOUns-Bg9kWWSksG66CkT17jH76KZrPZnO5BwALJZrTTF_zl0wg8zVer9aJtehdR3U4blhyuTV972DUaTWbpL5mfbe37HXmIh0RBVtfFES90HwXA4AgGo61EexEwANyWH5flEGkEGtN8CgjMcQVpC5_17eRFD-TtjgeXl7gea0AA4bm3BAaRpAA2OlpAEGBOVMBdcOOejrVohibiw1iOMsKQADlUApURrX4y9BOEx5RNEbdxPYziZLkxhRAmJTHUXCDAKIABrDCDkvWNUxMRMdlpXDAkUGAmBWHlLwA1NbMdeyJ25PlOxc2B3JfXDvMdXzNX8xzpFk-SHgdYLXLC-K9IMn1O0izVoqBWLuV0-TFOcttQuYCEEv0wyvN7Q8gW7eoXkCV4aECUBIFgRAIGgxhsDwIgyDydrwFCRA1DgdgimcQhSEKN08leKggA)

### Steps to Reproduce

1. Create a series of type `graph`
2. set `labelLayout.draggable` to `true`

### Current Behavior

`labelLayout.draggable` works for node labels but not for edge labels.

### Expected Behavior

Since `labelLayout`'s position parameters (`x`, `y`, `dx`, `dy`) DO affect the edge label, I would assume that `draggable` should work too.

### Environment

```markdown
- OS: Manjaro
- Browser: Firefox
- Framework: eCharts 5.4.2
```

### Any additional comments?

_No response_

Start with the linked minimal reproduction and a graph series using labelLayout.draggable set to true. Compare the existing node-label behavior with edge labels and trace the label layout and dragging entry points; done means edge labels can be dragged consistently with node labels while the existing x, y, dx, and dy behavior remains intact.

Written by the indexing model from the issue text.