Categorize synteny tracks in track selector according to reference or query relative mode

[cmdcolin]

specifically when you are viewing synteny tracks in the linear genome view.

some precedent for this is the session tracks, this is an automatically generated category

there is a bit of jargon in the title but the crux of the issue is you can have a hg19VsHg38 track, where hg19 was aligned to hg38. That means hg38 was the target of the alignent, hg19 was the query. You can also have the reverse. This would result in two different synteny tracks. Both synteny tracks would be viewable in the linear genome view track selector when you are just browsing e.g. hg19

It may help users to automatically organize these as 'query relative' or 'reference relative' with an added category

discussion motivation thread #4324

[cmdcolin]

Another alternative is hiding one of them. JBrowse has the ability to show the reverse as well because there could be complementary information, but some users might just want to hide one set