ENYO-2367: include enyo widgets in CSS style editor implementation

Summary: implementation done for;
* BACKGROUND-STYLE
* BORDER-STYLE
* FONT--STYLE
* PADDINGS-MARGINS
* TEXT-STYLE

Using enyo widgets like color picker, slider, picker, input text.

WARNINGS:
* **Ready for Review FIRST**.
* Follow-up JIRA ENYO-2560 is created. This JIRA will take in account the user feedbacks.

Enyo-DCO-1.1-Signed-off-by: Marie-Antoinette de Bonis-Hamelin (Marian)
marie-antoinette.de-bonis-hamelin@hp.com

@yves-del-medico Thanks to Yves to handle this pull request.