Iterate on layer and timeline editing to improve usability

[lklyne]

• The select all in the activity layer should be sticky and floating at the bottom of the list. With 10,000 activities it will be hard to get to
• Nice to have request: when loading a view on a different plan, show errors if there are parts that don’t line up. (added to Revisit how errors in the console are grouped, reviewed, and dismissed #325)
• Probably should think through the responsiveness of the y-axis ticks. Name field is long, and the tick increments are short numbers. Would be nice to dedicate space more appropriately. (Should be considered in new design direction).
• Bottom and top should be reversed in layers list. Bottom of list should represent the last item in the stack. As it currently stands items on the top are rendered on the bottom.
• Hard to know what data is associated with what axis labels. Work around to name the layers appropriately, but could be useful to have color coding.