TimeSeries: MultiChannel vertical misallignment with other Channels

Bug: [MultiChannel](https://labelstud.io/tags/timeseries.html#MultiChannel) causes x-axis misalignment in the UI; [Reproducable example in the playground](https://labelstud.io/playground/?config=%253CView%253E%253Cbr%253E%2520%2520%253CTimeSeries%2520name%253D%2522ts%2522%2520value%253D%2522%2524timeseries%2522%2520valuetype%253D%2522url%2522%2520timeColumn%253D%2522time%2522%2520timeFormat%253D%2522%2525Y-%2525m-%2525d%2520%2525H%253A%2525M%253A%2525S.%2525f%2522%253E%253Cbr%253E%2520%2520%2520%2520%253CMultiChannel%253E%253Cbr%253E%2520%2520%2520%2520%2520%2520%253CChannel%2520column%253D%2522velocity%2522%2520%252F%253E%253Cbr%253E%2520%2520%2520%2520%2520%2520%253CChannel%2520column%253D%2522acceleration%2522%2520%252F%253E%253Cbr%253E%2520%2520%2520%2520%253C%252FMultiChannel%253E%253Cbr%253E%2520%2520%2520%2520%253CChannel%2520column%253D%2522velocity%2522%2520%252F%253E%253Cbr%253E%2520%2520%253C%252FTimeSeries%253E%253Cbr%253E%253C%252FView%253E%253Cbr%253E%253Cbr%253E%253C%21--%2520%257B%253Cbr%253E%2520%2520%2522timeseries%2522%253A%2520%2522https%253A%252F%252Fapp.heartex.ai%252Fsamples%252Ftime-series.csv%253Ftime%253Dtime%2526values%253Dvelocity%25252Cacceleration%2526tf%253D%252525Y-%252525m-%252525d%252B%252525H%25253A%252525M%25253A%252525S.%252525f%2526type%253Dcsv%2522%253Cbr%253E%257D%2520--%253E).

When using MultiChannel, the chart is slightly shifted to the left to leave space for the secondary y-axis. This results in vertical misalignment between other Channels and the MultiChannel (see screenshot below).

This happens regardless of whether `showYAxis` is set to true or false.