Try reducing the component hierarchy for Group block

[pinarol]

We are facing with a crash when we nest too much in the Group block.

The root cause analysis made by @dratwas shows that the crash is related with the following line where there's a max limit in calculating layout:
https://href.li/?https://github.com/facebook/react-native/blob/master/React/Views/RCTShadowView.m#L156-L182

We should try to address that issue separately, but apart from that, let's also take a look inside our code and see if there's unnecessary layers in the component hierarchy. block-list/block.native.js looks especially worth investigating about this.

[pinarol]

I think the new bordering logic helped us make this better, so closing this or now.