Adopt index-based instead of name-based argument config

[chr-hertel]

If I am not mistaken, but I am currently on a phone 📱, we don't use named argument in Symfony, but index based assignments.

cc @Nyholm

Ofc in an extra PR

Originally posted by @OskarStark in #74 (comment)

[stof]

The BC promise of Symfony indeed excludes argument names (except for attribute constructors) for a few reasons:

• when using an interface, argument names are unreliable (PHP does not enforce that implementations use the same argument names, and runtime evaluation of the named arguments is based on the implementation, not based on the type available during static analysis)
• our process for refactoring method signatures (when wanting to remove an argument) is not compatible with being BC with argument names
• when wanting to change what gets injecting in an argument, keeping BC for the name would require keeping the old name forever
• it is in practice almost impossible to keep BC for both positional and named arguments when changing a method signature (which would mean never changing a method signature except by adding new arguments at the end, which would be much more restrictive for maintainers than the current policy)

It would be great for this project to rely on the same BC policy than other Symfony projects to provide clear expectations.

[OskarStark]

@yceruto while you are on the bundle config, would you like to take care?

[yceruto]

@OskarStark I’d prefer to do it in a separate PR