document editor: add a date time picker for ngx-formly

[Garfield-fr]

• Adds primeng library.
• Adds a new date time picker (use primeng).

Co-Authored-by: Bertrand Zuchuat bertrand.zuchuat@rero.ch

[jma]

I would change the commit message as follow: Type: add date time picker -> document editor: add a date time picker for ngx-formly