Ensure mosviz viewers are linked for MOS use case

[eteq]

Right now the MOSViz data viewers (i.e. everything except the table) move independently from one another. To meat the typical science needs the viewers should be tied together in a way that makes sense for a multi-object spectrum dataset. Specifically:

• [x] The 2d spectrum viewer (currently upper right) should have its x-axis permanently tied to the 1d spectrum viewer (currently middle-right). These should always be aligned when either is panned around. (see also #239 about hiding the 2d viewer's axis labels)
• [ ] The image viewer (currently upper left) should have its "y-axis" aligned to the 2d spectrum. For "y-axis" to make sense in this context, the image viewer should be rotated such that the slit is straight up-and-down (which is not necessarily the native alignment of the image).
• [ ] The image viewer (currently upper left) should have an optional status of being un-aligned, probably best implemented as a checkbox somewhere in the UI. This would then allow the user to pan around and examine the context of the slit. If they re-check it, it should pop into the view aligned with the relevant slit again.

[rosteen]

The first task was done in https://github.com/spacetelescope/jdaviz/pull/264