[12.x] Fix group imports in Blade @use directive

[osbre]

PHP natively supports group imports since PHP 7.0:

use MySpace\{Foo, Bar};

Currently, the @use directive mistakenly treats these as aliases. For example,

@use(MySpace\{Foo, Bar})

Results in:

use MySpace\Foo as Bar.

This PR fixes it so that the blade code above, produces output equal to PHP's original feature:

use MySpace\{Foo, Bar};

[osbre]

Marking as draft since this PR currently breaks some behaviour that wasn't covered by tests. I have made a fix to the tests to document the behaviour that this PR would've broken: #55462

[osbre]

Alright. Updated, now nothing breaks.