Content padding support

[naqvitalha]

Description

resolves #621

We've had to ignore horizontal padding on vertical lists and the opposite for horizontal ones due to layout complexities. This PR solves the problem and avoids any performance regression.

Motivation

Doing this now was important because, in regular FlashList, padding can simply be added to items but in masonry, we change the order of items and it's quite complex to add something as simple as content padding. Developers need to render and update items based on their columns.

Reviewers’ hat-rack 🎩

• Try playing with contentContainerStyle in any of the sample.
• Check performance regression (there isn't any but doesn't hurt to check)

Checklist

• I have added a changelog entry following the Keep a Changelog guidelines.

[sebastienlabine]

Thank you. When should we expect this? Can't fully migrate our code to flashlist because most of our components uses horizontal padding making.

[naqvitalha]

@sebastienlabine It'll take sometime. However, for everything other than masonry you can easily apply padding to your items. There's no need to wait for this.
It's not as convenient but still worth it given the boost you get.

[naqvitalha]

@fortmarek Can you take a look at this when you have time? It'll be very helpful for the community

[fortmarek]

🎩 'd and everything works as expected. Just a couple of nits but nothing that would block merging this 👏