[Symfony] Make grabService use the special test service container if available

[burned42]

As @ThomasLandauer reported via #5073 quite some time ago, grabService seems to be somewhat broken for newer Symfony versions (>= 4.1 ?).

With Symfony 4.1 a special service container was added that can be accessed via test.service_container for testing purposes which also provides access to private services:
https://symfony.com/doc/current/testing.html#accessing-the-container

I also added a test to the symfony-demo project at Codeception/symfony-demo@master...burned42:add_service_container_test and if this PR will get accepted then I'd also open a PR for that branch.

I tried to let the CI run with these tests with:

• above mentioned branch: https://travis-ci.org/burned42/Codeception/builds/592171088
• branch 3.1 as base: https://travis-ci.org/burned42/Codeception/builds/592157281

So to me it seems like the issue is solved with these changes. Maybe someone more familiar with the Symfony module can also take a look at this :)

[Naktibalda]

Looks good to me, but I am not familiar with Symfony,
I'm afraid that we have no Symfony experts to review it.

[ThomasLandauer]

If you tell me how to get this commit into my project (composer.json?), I will double check if it's working.

[burned42]

@ThomasLandauer to use the version from my branch add this to your composer.json

    "repositories": [
        { "type": "vcs", "url": "https://github.com/burned42/Codeception" }
    ]

And change the line in require-dev from
"codeception/codeception": "3.1",
to
"codeception/codeception": "dev-fix_grabService_symfony4 as 3.1",

FYI: For me composer hit the API rate limiting from github and provided me with a link to get a token. After generating and entering this token it installed the version from my branch into my project.

[Naktibalda]

Does it work?

[ThomasLandauer]

Sorry guys for being so late! Since burned42:fix_grabService_symfony4 is gone now, I just updated to Codeception 3.1.2.

It works for me in both Symfony 4.3 and 3.4 :-)