Register `ResolverInterface` and `MutationInterface` for auto configuration

[ruudk]

Q	A
Bug report?	no
Feature request?	yes

We are in the process of upgrading our codebase from Symfony 3.3 to Symfony 4 and want to use autowire. We were quite surprised to find out that OverBlogGraphQLBundle has it's own "auto wire" (auto mapping). We disabled that option (overblog_graphql: definitions: auto_mapping: false) but then found out that the bundle doesn't auto configure the interfaces with the given tags.

By adding the following 2 lines to our own extension, it worked:

$container->registerForAutoconfiguration(ResolverInterface::class)->addTag('overblog_graphql.resolver');
$container->registerForAutoconfiguration(MutationInterface::class)->addTag('overblog_graphql.mutation');

Is there a reason this is not added? I can make a PR to add it.

[mcg-web]

This could not be added to 0.11 releases since this feature was introduce in Symfony +3.3 and we supports +3.1. For 0.11 we recommends using config file to do the work:

services:
    _instanceof:
        GraphQL\Type\Definition\Type:
            tags: ['overblog_graphql.type']
        Overblog\GraphQLBundle\Definition\Resolver\ResolverInterface:
            tags: ['overblog_graphql.resolver']
        Overblog\GraphQLBundle\Definition\Resolver\MutationInterface:
            tags: ['overblog_graphql.mutation']

    App\GraphQL\:
        resource: '../src/GraphQL'

PR are welcome for 0.12-dev (master) version since auto_mapping config was totally removed.