Expression Viewer - Spatial Panel improvements

[adkinsrs]

After testing I decided to use Plotly to make the spatial plots + Panel to split plots into multiple panes in an embeddable panel app.

November 22, 2024 standup

Showed Panel-based viewer to Ronna and co. Feedback was well-received. She envisioned a situation where you can take unannotated clusters (like the single-cell workbench), and when you select a region to zoom in or select a specific cluster, it will recluster within that region. I did note the scope of the panel currently was for the gene expression viewer, but we can make it work for other tools too.

Other things:

• Zoomed in expression panel should have a different colorbar color, in case user does not realize the original and zoomed in scales are different.
• I need to fine-tune cell filtering to better filter out cells that are in the negative space of the image
• I also need to figure out the bug where the zoomed in plot pans to another part of the axis where the selected data is. Hasn't occurred today (as of writing this) but when it did occur it wasn't repeatable.
• When you select a region from one plot, move the selected region on the other plot, or disable selection on that plot.

Originally posted by @adkinsrs in #913 (comment)