Fix DebugCommand dependency injection

[jdecool]

Q	A
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Tests pass?	no
Documented?	no
Fixed tickets	N/A
License	MIT

In one of our projects, we decorate QueryResolver and MutationResolver for our needs.

But currently, the DebugCommand depends on concrete implementations instead of interfaces.
So when we run the bin/console list, Symfony crash because of the dependency injection.

This PR updates the DebugCommand constructor to inject FluentResolverInterface instead of concrete implementations.

[mcg-web]

This change can introduce a break change before php 8, can we introduced this from 0.14 @jdecool ?

[jdecool]

@mcg-web It could.

But I don't understand why it could introduce a BC before PHP 8.
All class used implement the FluentResolverInterface so they can be replaced by the interface they use no ?

[ruudk]

The class it not final, so it could be extended. But it shouldn't be an issue, see https://3v4l.org/OZ86V

[mcg-web]

My bad since it's the construct , it is not consider as a BC.