[Intl] Integrated ICU data into Intl component #1

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #11447, #10807
| 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~~ merged+rebased now).

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.~~

The data is included as text/binary now. Git takes care of the compression.

Before this PR can be merged, I would like to find out what the performance difference between the two formats is in real applications. 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. I'll also try to create some more realistic benchmarks.

If JSON is not significantly slower/takes up significantly more memory than the binary format, we can drop the binary format altogether.
the type is missing, making it invalid phpdoc. Either fix the phpdoc or remove it (same in all other methods