Allow multiple (>2) genome synteny/comparative view

[dirkjanvw]

Is your feature request related to a problem? Please describe. For multiple genome comparisons, it is quite hard to find a genome browser that can handle it. I know that JBrowse2 can visualise 2 genome comparisons with the "linear synteny view", but if I understand correctly more than 2 is currently not possible. However, this would be very useful for some of my applications (where we compare data of 4 related species).

Describe the solution you'd like Some way of visualising >2 genome comparisons via synteny or alignment tracks.

Describe alternatives you've considered What I currently do is: I take my multiple genome file and extract pairwise comparisons. These pairwise comparisons I then all add separately to config.json file. This is not really sustainable, though, as the number of pairwise comparisons explodes rapidly.

Additional context I saw "linear comparative view" in the dropdown menu when opening an empty session and intuitively I thought this might be the place to implement such a feature? Not sure what the difference would be to "linear synteny view" as what it implements for 2 genomes might be extendable to >2.