Blockbase: Opt-in to support for border controls

[kjellr]

Blockbase should opt-in to custom border controls, as per the notes in this comment:

	"settings": {
		"defaults": {
			"border": {
				"customColor": true,
				"customRadius": true,
				"customStyle": true,
				"customWidth": true
			}
		}
	}

[MaggieCabrera]

Yeah, I thought I remembered adding these controls. The thing is not all blocks surface them the same way but these settings are already on Blockbase. You can test them on the Group block:

[pbking]

Indeed, just tested in Quadrat too and it's working nicely as expected. Interestingly I see a slightly different panel layout that pictured above but it works smashingly. I didn't even know it was there. :P

I believe that the blocks will pick up the controls as support is expressed for them. I don't believe there's anything more to do here. It's already awesome!

Closing this as done. Please reopen if I missed something!