feat(babel-preset-app): add support for core-js 3

[exreplay]

This feature is currently unstable. The problem is that a lot of dependencies are currently still using core-js 2 and if the user not explicitly installs core-js 3, modules are not resolved correctly.

UPDATE 30.12.19
The support is now given but if the user wants to use core-js 3 the packages have to be installed in the root of the project. Aver still has version 2 installed internally to prevent projects from breaking.

[codecov]

Codecov Report

Merging #74 into development will decrease coverage by 1.05%.
The diff coverage is 100%.

@@               Coverage Diff               @@
##           development      #74      +/-   ##
===============================================
- Coverage          100%   98.94%   -1.06%     
===============================================
  Files               16       20       +4     
  Lines              156      189      +33     
  Branches            18       24       +6     
===============================================
+ Hits               156      187      +31     
- Misses               0        1       +1     
- Partials             0        1       +1

Impacted Files	Coverage Δ
packages/config/lib/configs/renderer.js	100% <ø> (ø)	⬆️
packages/babel-preset-app/lib/getPolyfills.js	100% <100%> (ø)
packages/babel-preset-app/lib/index.js	100% <100%> (ø)
packages/babel-preset-app/lib/polyfillsPlugin.js	80% <0%> (ø)
babel.config.js	100% <0%> (ø)

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