Move common config files to root

[miltoneiji]

Typescript and jest config files are very similar between the packages. Move them to root and extend them in the packages.

[miltoneiji]

Figure a way to:

• [ ] have a nice output when executing tests from root
• [ ] the possibility to execute tests from inside a package

[sthuber90]

thank you for your great example. I stumbled across it looking for a solution why my tests fail, when they reference to a other package. My solution, with jest as a test runner, was to use ```

moduleNameMapper: {
    '@foo': '<rootDir>/../../packages/foo/src/'
}

https://jestjs.io/docs/en/configuration.html#modulenamemapper-objectstring-string--arraystring

Hope this may help people coming across here too. It enabled me to run tests within a package or on root level, without having to build sources beforehand