feat: add contentStyle to TextInput

[guilherme-ferraz1]

Summary

Adds contentStyle prop to TextInput as requested in #3434
This prop allows to pass style props directly to the input itself, not the container.

Test plan

The tests and examples are already updated.
Tested on both IOS and Android with StyleProp<ViewStyle> props like paddingLeft, backgroundColor etc.

Custom style input example:

contentStyle={{ paddingLeft: 50 }}

[callstack-bot]

Hey @guilherme-ferraz1, thank you for your pull request 🤗. The documentation from this branch can be viewed here.

[gmferraz]

@lukewalczak unit test added, prop name changed and minor issues fixed

[lukewalczak]

Hey @gmferraz, I've analyzed your PR one more time and have two requests, please:

• resolve conflict
• rename prop to contentStyle - it's more appropriate than containerStyle proposed previously.

I would like to do the release tomorrow, so please handle it if possible 🙏🏽

[gmferraz]

@lukewalczak done :)