[Vue][React][Svelte] Fix components assets compilation on Windows server

[Kocal]

Q	A
Bug fix?	yes
New feature?	no
Docs?	no
Issues	Fix #...
License	MIT

Following #2816, this PR fixes the controller.js files generation when the Symfony app is running on Windows server:

Testing 
F...                                                                4 / 4 (100%)

Time: 00:01.229, Memory: 30.00 MB

There was 1 failure:

1) Symfony\UX\Vue\Tests\AssetMapper\VueControllerLoaderAssetCompilerTest::testCompileDynamicallyAddsContents
Failed asserting that 'import component_0 from '../../vue/controllers/MyVueController.js';\n
import component_1 from '../../vue/controllers/subdir/DeeperVueController.js';\n
export const components = {"MyVueController": component_0, "subdir\DeeperVueController": component_1};' contains ""subdir/DeeperVueController": component_".

D:\a\ux\ux\src\Vue\tests\AssetMapper\VueControllerLoaderAssetCompilerTest.php:72

I was able to set-up a Windows VM to ensure the PR fixes the problem (tip: don't use a remote VM in a train... 🙂)

Before, you can see that subfolder\Goodbye is interpreted as subfolderGoodbye, meaning that is not possible to use subfolder/Goodbye Vue component (I made a typo in the Twig template, but it has no effect):

With the patch, the path now contains / instead of \, the component subfolder/Goodbye is now usable:

[Kocal]

I only tested Vue components btw, didn't have time for React and Svelte, the logic is the same