Align channels of time series manually

**Is your feature request related to a problem? Please describe.**
For some labelling tasks, it is useful to manually align multiple time series, for example when they have a time delay. Currently, it is not possible to synchronize shifted channels within the same time series. More specifically, I need to look at 96 pairs of channels, but currently if I add 2 time series projects, each with 96 channels, it is very difficult to align the corresponding pairs between the 2 time series.
**Describe the solution you'd like**
I would like it to be possible to manually shift individual channels of the same time series while leaving the other channels still. This is so that multiple time series can be synchronized manually. However, when labels are added, we want the channel-specific time to appear in the label.

**Describe alternatives you've considered**
Alternatively, it should be possible to be able to toggle visibility on/off for certain channels so that only the 2 channels of interest are visible and can be properly aligned.

**Additional context**
Add any other context or screenshots about the feature request here.