feat: locales support

[sascha245]

PR Checklist

• Fix linting errors
• Label has been added

Change information

• Add translated locales from element-ui repository
• Add basic locales service
• Replace hard coded text by locales in src/date-picker
• Replace hard coded text by locales in src/pagination

Note: Not all components have been translated yet.

Usage

// Import locales services
import { ElLocalesService } from 'element-angular';

// Import needed locales
import localesEn from 'element-angular/release/locales/lang/en';

// Inject service
constructor(
  private elLocales: ElLocalesService
) {
}

You can then change used locales with

this.elLocales.use(localesEn);