Improve study pane configuration

[mattrussell36]

The Chore

It would be useful to be able to pass callback to the chart which will be called when the internal panes change size. Additionally it would be good to be able to set the initial size

ACs

• I can set the height of the study panes
• Studies should NOT grow proportionally when the chart canvas gets larger. ALL extra size when the chart grows should go to the main chart.
• Studies should only shrink when the chart area gets smaller IF necessary to fit the chart and all the studies
  • Something like: if the chart would get smaller than the biggest study (because of resizing or the adding of studies), reduce ALL of the studies proportionally as the canvas gets smaller, BUT don't persist the studies temporarily smaller sizes (do persist if they are then manually sized though)
• The chart should greedily take the extra space.

Tasks

• Expose pane onChange callback
• Allow setting initial pane size in px/%
• Adjust pane resizing logic
• Dev
• Test

Additional details / background info

[bwallacee]

@mattrussell36 if I have multiple studies open and resize a study below another to be taller, it shrinks the study above. And vice versa, if i shrink a study below, the stufy above grows.

I would have though that the study above would remain the same size in both scenarios?