[ImageLoader] Simplify getSize implementation, call failure callback when decoding fails

[lkinasiewicz]

Fixes #2749.

1. Simplified getSize implementation, so that there is no possibility for infinite timers.
2. Added handling of decoding failure.
3. Added unit tests for getSize.

[codesandbox-ci]

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Latest deployment of this branch, based on commit f8ddd30:

Sandbox	Source
react-native-web-examples	Configuration

[CrashBashMD]

looks like it was over complicated before

[quantizor]

I decided to fork this repo to apply the patch and make it available: https://www.npmjs.com/package/react-native-web-fork

The easiest way to use it is probably this package.json override:

{
  "overrides": {
    "react-native-web": "npm:react-native-web-fork"
  }
}

There are other patches applied as well, noted in the package README up top.