[GB 2.0 beta] Have border radius with linked sides by default

[quantumleap33]

Description

In the borders section in the block editor, the borders have all sides linked by default, whereas the border radius displays all sides by default. It would be nice for those to also appear linked. Most of the times, border radius values are applied to all sides at once.

References:

https://i.imgur.com/Po27rmG.png

[diggeddy]

I agree on this. As we already link border by default - it should follow that pattern. And in most use cases borders are linked.