App crashes when closing linear vs. ref view with track open

[elliothershberg]

If you open a linear vs. ref synteny view for an alignment, open a track on one of the views, and then close the linear vs. ref view, the app crashes:

Steps to reproduce:

1. Open a linear view
2. Open an alignments track
3. Open the linear vs. ref synteny view for an alignment
4. Open a track on one of the linear views
5. Close the linear vs. ref synteny view

I came across this when working on #1322 , can provide more info if needed!

[rbuels]

This is one example of why we need to do everything we can not to have ts-ignores!

[cmdcolin]

Dup of #1411

[cmdcolin]

Note that #1442 would fix

[elliothershberg]

@cmdcolin Ahh oops, was looking around and didn't see that one. I'll go ahead and close this then 👍