Add linkingId field to the y channel

[etowahadams]

To address: #399

Proposal: Add linkingId field to the y channel:

Example:

"y": {"field": "peak", "type": "quantitative", "axis": "right", "linkingId": "my-ID"}

Tracks that share the same linking ID will share the same y-axis

Implementation details:

• Use valueScaleLocks in the HiGlass config to lock the y-axis together. Here is an example:

"valueScaleLocks": {
    "locksByViewUid": {
        "track1": "my-lock-group",
        "track2": "my-lock-group"
    },
    "locksDict": {
        "my-lock-group": {
            "track1": {
                "track": "track1",
                "view": "view1"
            },
            "track2": {
                "track": "track2",
                "view": "view1"
            },
            "uid": "my-lock-group"
        }
    }
},

[etowahadams]

It seems that the proposed strategy, using valueScaleLocks, does not immediately work for linking the y-axis.

I turned on the HiGlass interface and tried to lock the scale values on two Gosling tracks, but didn't see any changes.

Screen.Recording.2024-05-08.at.12.11.00.PM.mov

In HiGlass, value scale locks are handled in handleValueScaleLocked
https://github.com/higlass/higlass/blob/335f4eea6445d07baa5eda2e66077dca461b7777/app/scripts/HiGlassComponent.jsx#L3133

This calls a function to sync value scales, which updates this.valueScale
https://github.com/higlass/higlass/blob/335f4eea6445d07baa5eda2e66077dca461b7777/app/scripts/HiGlassComponent.jsx#L1354

As far as I can tell, most HiGlass tracks use this valueScale to get positions to draw graphics. However, Gosling uses a scale that is stored in GoslingTrackModel to get positions instead. This is why nothing happens even when you select for the value scale to be locked.

We would have to change Gosling so it uses this.valueScale, or change the scale in GoslingTrackModel whenever there is a change in valueScale so that the track draws using this new axis.