Remove redux dependencies from JSON Forms

[TheZoker]

Removes redux as a direct dependency.

• Redux is removed from the material package (not needed anyway)
• The missing types have been replaced with own types
• jsonformsRecducer was removed from the core package (not used anyway)
• All material tests have been rewritten to run without redux
• react-redux was moved from the peerDepedencies to the optionalPeerDependencies
• The jsonFormsReduxContext is now available under @jsonforms/react/redux

import { jsonFormsReduxContext } from `@jsonforms/react/lib/redux`;

Related issue: #1537

[sdirix]

I tried it with the React seed and was successfully able to compile and run JSON Forms without installing Redux 🎉

However I was not able to run the fallback Redux variant as the jsonformsReducer is now missing. Please check whether we can restore this export.

Please also check:

• All tests should run. Currently the core tests (and maybe more) are failing.
• All example apps should run. Currently at least the React-Material example app doesn't start.

[sdirix]

Looks good! Some minor comments.

[sdirix]

Build is failing

[coveralls]

Coverage decreased (-0.4%) to 88.383% when pulling 4f2c970 on TheZoker:remove-redux into 0608fff on eclipsesource:master.

[sdirix]

The typings for the jsonFormsReducerConfig fail when trying to use a built version. It seems each of the reducers should declare an appropriate Reducer<State,Action> type instead of relying on automatic type conversion.

[sdirix]

LGTM