[Intl] Integrated ICU data into Intl component

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #11884 
| License       | MIT
| Doc PR        | -

This PR is an alternative implementation to #11884. It depends on #11906 and #11907 being merged first (these are included in the diff until after a merge+rebase).

With this PR, the ICU component becomes obsolete. The ICU data is bundled with Intl in two different formats: JSON and the binary ICU resource bundle format (version 2) readable by PHP's `\ResourceBundle` class. For a performance comparison between the two, see my [benchmark](/webmozart/json-res-benchmark).

The data is contained in two zip files: json.zip (2.6MB) and rb-v2.zip (3.8MB). The handler

```php
\Symfony\Component\Intl\Composer\ScriptHandler::decompressData()
```

needs to be added as Composer hook and decompresses the data after install/update.

Before this PR can be merged, I would like to find out what the performance difference between the two formats is in real application. For that, I need benchmarks from some real-life applications which use ICU data - e.g. in forms (language drop-downs, country selectors etc.) - for both the JSON and the binary data. You can force either format to be used by hard-coding the return value of `Intl::detectDataFormat()` to `Intl::JSON` and `Intl::RB_V2` respectively.