core: settings

[dsebastien]

Add support for settings

• [ ] preferred language
• [ ] customization of settings through the ui (cog wheel) with a dedicated "dialog"
• [ ] effects implementation (persist)

For the customizations: create a reusable component for displaying user settings. The component should be extensible: expose default settings valid for all Stark applications but also let applications define additional settings.

The controller should be injected with the SettingsService and leverage the ISettingsService interface to manipulate the settings.

Let apps wire it up to avoid lock-in.

Current settings supported by Stark:

• preferredLanguage (selection + possibility to persist it via the PERSIST_PREFERRED_LANGUAGE action)

Settings should be available via a cog wheel on top right of the application (next to app data?) and should display a dialog.

[dsebastien]

In our initial design, we'ved efined the following (partially implemented in Stark 9.X):

• Settings model class
• SettingsActions class with actions
• SettingsReducer to maintain the state in the Redux store
• SettingsEffects to handle side-effects
• ISettingsService interface to expose the settings API (should be used by components)
• SettingsService implementation