feat(side-by-side): Assorted QA and Polish Items

[seve]

Going to list some variously sized items as I think of them, feel free to add to this list as QA and UXR is conducted.

Items

• Responsive panel
  • Should the panel be responsive to the viewport size? Both the side panel and the scatterplot are not currently.
  • Should the user be able to drag to resize the panel?
  • Should the user be able to move the panel?
• Cell count integration
  • The cell count can be a bit hard to read when there are cells behind
  • The text is also selectable, which can screw with lasso and pan
• Should we modify the dot size in the panel to prevent density issues?

[tihuan]

@niknak33 Adding this to post launch ticket with P1. Please let me know if that works for you too thank you!