UPDATE "react-split-pane": "^0.1.74", to FIX an breaking issue

[ndelangen]

See here:
tomkp/react-split-pane#238

What I did

Update the packages inside /libs/ui

[codecov]

Codecov Report

Merging #2528 into master will increase coverage by 0.27%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2528      +/-   ##
==========================================
+ Coverage   16.87%   17.14%   +0.27%     
==========================================
  Files         307      307              
  Lines        7792     7815      +23     
  Branches      768      946     +178     
==========================================
+ Hits         1315     1340      +25     
+ Misses       5865     5728     -137     
- Partials      612      747     +135

Impacted Files	Coverage Δ
app/react/src/server/babel_config.js	66.66% <0%> (-10.76%)	⬇️
lib/ui/src/libs/key_events.js	23.25% <0%> (ø)	⬆️
addons/a11y/src/components/Report/Info.js	0% <0%> (ø)	⬆️
addons/jest/src/components/PanelTitle.js	0% <0%> (ø)	⬆️
lib/codemod/src/transforms/update-addon-info.js	50% <0%> (ø)	⬆️
...res__/update-addon-info/update-addon-info.input.js	0% <0%> (ø)	⬆️
...les/ui/components/left_panel/stories_tree/index.js	38.46% <0%> (ø)	⬆️
lib/ui/src/modules/ui/components/layout/index.js	30.07% <0%> (ø)	⬆️
addons/info/src/components/PropTable.js	21.36% <0%> (ø)	⬆️
addons/knobs/src/components/types/Array.js	29.72% <0%> (ø)	⬆️
... and 55 more

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