Add a dedicated file deletion for unconfigure recipes

[maxhelias]

Re-open #667

In this way, we correct the deletion of the same file imported by 2 recipes.
Factoring in this way would allow us to remove the $lock parameter passing in the unconfigure method and with a little more work in the configure.

WDYT about this way ? Can I continue in this direction?

[maxhelias]

Outdated and should be resolve in #845

[nicolas-grekas]

@maxhelias up to rebase this for 2.x?
It looks like we might need this: removing phpunit-bridge currently removes files that should be kept for phpunit when it remains and you had the answer apparently.

[maxhelias]

@nicolas-grekas Yes, of course, I think I'll have to work on it again after all this time 😅