Add focusable to Pressable

[chrisglein]

From Keyboarding in React Native Desktop document:

Property that determines whether this View, Touchable should be focusable with a non-touch input device, eg. receive focus with a hardware keyboard. Setting the property to true will make that View compoonent become a part of tabbing loop.

• Add focusable to Pressable

[NickGerleman]

We should already have this. Stock Pressable will set the inner view to Focusable so long as the outer Presasble is not explicitly set not to be focusable See https://github.com/facebook/react-native/blob/0.63-stable/Libraries/Components/Pressable/Pressable.js#L213-L226

We can keyboard between pressables in the RNTester example with this.

[NickGerleman]

Going to close this one since I think there's nothing left to do. @chrisglein please reopen if I missed something here.

[elicwhite]

It might not be necessary, but I could expect Pressable to pass in the state object hovered and focused, where right now it just passes pressed. https://github.com/facebook/react-native/blob/0.63-stable/Libraries/Components/Pressable/Pressable.js#L222-L223

hovered is probably more valuable than focused, but the API was designed to enable platforms to add more things like that.