Pf4 dark mode

[damianpm]

What this PR does / why we need it:

PatternFly is switching by default to dark theme.
See:
https://www.patternfly.org/v4/documentation/react/components/page#examples
And:
https://www.patternfly.org/v4/documentation/react/components/nav

Verification steps

npm run update-dependencies

Special notes for your reviewer:

Before:

After:

Deployed to preview env

[josemigallas]

The animation in vertical nav is not working. It's easier to spot when closing a menu:

This is how it should look like:

Something wrong with pf-m-dark maybe? I couldn't find what's causing it.

[codecov]

Codecov Report

Merging #1525 into master will decrease coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           master   #1525      +/-   ##
=========================================
- Coverage   93.01%     93%   -0.01%     
=========================================
  Files        2516    2516              
  Lines       83600   83570      -30     
=========================================
- Hits        77757   77722      -35     
- Misses       5843    5848       +5

Impacted Files	Coverage Δ
lib/tasks/multitenant/tenants.rake	41.5% <0%> (-5.67%)	⬇️
app/models/user.rb	94.42% <0%> (-0.75%)	⬇️
spec/acceptance/api/user_spec.rb
spec/acceptance/api/cms_template_spec.rb	100% <0%> (ø)

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[damianpm]

@josemigallas I think there are no transitions or animations anymore, if you look at the examples, they don't have it:
https://www.patternfly.org/v4/documentation/react/components/nav#expandable

[thomasmaas]

But there is still some sort of animation going on in preview…

[damianpm]

Merging and creating a new issue to investigate if the "jump" is a real issue or just something new in PF
https://issues.redhat.com/browse/THREESCALE-4252

Creating new issue to further investigate