ENYO-2431, ENYO-2427: Updated layout.design

* ENYO-2427: Updated layout.design: removed useless "isContainer" and "content". Added "isRepeater" options to "list" kinds
* ENYO-2431: Cleanup of "inline" properties in layout.design
* ENYO-2431: Cleanup of "inline" properties in layout.design
* ENYO-2427: Updated layout.design to better handle LIST in Ares Designer

Enyo-DCO-1.0-Signed-off-by: Yves Del Medico <yves.del-medico@hp.com>