refactor: Image component

[mthahzan]

Description

A minor refactor of the fallback logic has been made to improve the performance by eliminating a call to create an array on every render. This has been replaced with a logical operation during the onError event.

Additionally, this refactors the exported component to be more flexible in their usage. This deprecates the named import of the component and introduces a default import in place of that.

// This is deprecated
import {ImageLoader} from 'react-native-image-fallback';

// This is the preferred way
import Image from 'react-native-image-fallback';

The deprecated named export will be removed on the next major version.

Some of the exported typings have also changed, but I do not consider them to be "breaking changes" per se. But this is a potential gotcha moment for consumers.

Fixes #38

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules