Responsive dashboard design

[jemrobinson]

Updated the design to change on different screen sizes. Major differences are:

Summary

• width of columns in HeaderPanel, main map/legend panel and InfoPanel
• text sizes on small screens
• reflow of InfoPanel on small screens with the info cards moving underneath the histogram
• fixed margins/padding to ensure that different elements are cleanly separated
• removed default fixed-width offsets for x and y axes of histogram

Screenshots

I've tested on the most common screen sizes which are:

1920×1080 (8.89%)

1366×768 (8.44%)

360×640 (7.28%)

414×896 (4.58%)

1536×864 (3.88%)

375×667 (3.75%)

Closes #88