Burninate server-side rendering

[akx]

This PR removes the server-side rendering code.

• Every non-API URL will just always return the HTML skeleton without an attempt to render the app.
• Running with the serverRendering config option is now an error.

Refs: #405 #133 #58 #317 etc.

[codecov-io]

Codecov Report

Merging #413 into master will decrease coverage by 10.1%.
The diff coverage is 0%.

@@             Coverage Diff             @@
##           master     #413       +/-   ##
===========================================
- Coverage   26.87%   16.77%   -10.11%     
===========================================
  Files         117      116        -1     
  Lines        2590     2540       -50     
  Branches      436      425       -11     
===========================================
- Hits          696      426      -270     
- Misses       1596     1749      +153     
- Partials      298      365       +67

Impacted Files	Coverage Δ
server/getSettings.js	0% <0%> (ø)	⬆️
server/render-middleware.js	0% <0%> (ø)	⬆️
src/components/Footer.js	0% <0%> (-100%)	⬇️
src/getRoot.js	0% <0%> (-100%)	⬇️
server/Html.js	0% <0%> (-100%)	⬇️
src/utils/FormatRelativeTime.js	14.28% <0%> (-85.72%)	⬇️
src/views/Hearing/Sidebar.js	2.56% <0%> (-71.8%)	⬇️
src/App.js	14.28% <0%> (-71.43%)	⬇️
src/views/Hearing/Header.js	16.66% <0%> (-66.67%)	⬇️
src/components/SectionList.js	16.66% <0%> (-66.67%)	⬇️
... and 16 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b8dfb05...fc1bac7. Read the comment docs.