mgr/dashboard: Allow I18N when using "ng serve"

mgr/dashboard: Allow I18N when using "ng serve"

"ng serve" doesn't support i18n flags, so we need to define all language
specific settings in angular.json.

Then we can use them with the configuration flag, p.e.:
"ng serve --configuration=pt-BR"

We can also use this configurations for non production build, p.e.:
"ng build --configuration=pt-BR"

Set some global options, that will be shared by all configurations.

Signed-off-by: Tiago Melo <tmelo@suse.com>