Move polymer loader to peerDependencies

[Hypnosphi]

Issue: polymer-webpack-loader adds following line to processed files:

require('polymer-webpack-loader/register-html-template')

It means that the package should always be available on root level. We can't rely on npm hoisting for that, so we need to move it to peerDependencies

[codecov]

Codecov Report

Merging #3161 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3161   +/-   ##
=======================================
  Coverage   36.03%   36.03%           
=======================================
  Files         437      437           
  Lines        9464     9464           
  Branches      860      893   +33     
=======================================
  Hits         3410     3410           
+ Misses       5532     5493   -39     
- Partials      522      561   +39

Impacted Files	Coverage Δ
app/vue/src/server/utils.js	0% <0%> (-100%)	⬇️
lib/ui/src/modules/shortcuts/actions/shortcuts.js	22.41% <0%> (ø)	⬆️
lib/ui/src/modules/api/index.js	0% <0%> (ø)	⬆️
lib/ui/src/modules/ui/components/layout/index.js	29.28% <0%> (ø)	⬆️
addons/info/src/components/markdown/code.js	76.92% <0%> (ø)	⬆️
app/react-native/src/bin/storybook-build.js	0% <0%> (ø)	⬆️
...tions/src/lib/types/function/createFunctionEval.js	77.77% <0%> (ø)	⬆️
lib/ui/src/modules/ui/components/menu_item.js	19.14% <0%> (ø)	⬆️
addons/knobs/src/react/WrapStory.js	49.42% <0%> (ø)	⬆️
addons/knobs/src/components/types/Select.js	24.63% <0%> (ø)	⬆️
... and 64 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 3140df3...88d2fe2. Read the comment docs.

[ndelangen]

@stijnkoopal What do you think?

[stijnkoopal]

Not sure that we need this dependency still, but perhaps I'm missing something here.

[ndelangen]

Thanks! that doesn't sounds like a blocker tbh