PIM-1891 : cosmetic in grid attribute type config
PIM-1891 : introduce selector interface
PIM-1891 : add flexible value selector
PIM-1891 : ad media selector
PIM-1891 : add metric selector
PIM-1891 : add single option selector
PIM-1891 : add multi options selector
PIm-1891 : add prices selector
PIM-1891 : declare selectors as services
PIM-1891 : add a compiler pass to inject selector in selector extension