refactor(ui): get notification data (types, default values) from API

[fsamin]

WorkflowNotificationFormComponent
relies on

export const notificationTypes = ['jabber', 'email'];
export const notificationOnSuccess = ['always', 'change', 'never'];
export const notificationOnFailure = ['always', 'change', 'never'];

API provides those data from /notification/type and /notification/state

also i would like to handle this:

export class UserNotificationTemplate {
    subject: string;
    body: string;

    constructor() {
        this.subject = '{{.cds.project}}/{{.cds.application}} {{.cds.pipeline}} {{.cds.environment}}#{{.cds.version}} {{.cds.status}}';
        this.body = 'Project : {{.cds.project}}\n' +
                'Application : {{.cds.application}}\n' +
                'Pipeline : {{.cds.pipeline}}/{{.cds.environment}}#{{.cds.version}}\n' +
                'Status : {{.cds.status}}\n' +
                'Details : {{.cds.buildURL}}\n' +
                'Triggered by : {{.cds.triggered_by.username}}\n' +
                'Branch : {{.git.branch}}';
    }
}

on API Side, returned by /notification/type

The goal are:

• to know on API side if notification in the as-code format the the default ones or not
• having different default values for notification type

related to #3519