Adds sha argument to lint

What does this MR do?

Adds a sha argument to the CiConfig resolver.

Screenshots (strongly suggested)

example query:

{
  ciConfig(projectPath:"root/lost-highway", sha: "439cea8ac5a9a0bd272c8d78f092ec72fbd488ec", content: "before_script:\n  - bundle install\n  - bundle exec rake db:create\n\nrspec 0 1:\n  stage: build\n  script: 'rake spec'\n  needs: []\n  tags:\n    - ruby\n    - postgres\n  only:\n    - branches\n    - master\n\nrspec 0 2:\n  stage: build\n  allow_failure: true\n  script: 'rake spec'\n  when: on_failure\n  needs: []\n\nspinach:\n  stage: build\n  script: 'rake spinach'\n  needs: []\n  except:\n    - tags\n\ndeploy_job:\n  stage: deploy\n  script:\n    - echo 'done'\n  environment:\n        name: production\ndocker:\n  stage: test\n  script: 'curl http://dockerhub/URL'\n  needs: [spinach, rspec 0 1]\n  when: manual\n  except:\n    - branches\n\nafter_script:\n  - echo 'run this after'\n") {
    mergedYaml
  }
}

response:

{
  "data": {
    "ciConfig": {
      "mergedYaml": "---\nbefore_script:\n- bundle install\n- bundle exec rake db:create\nrspec 0 1:\n  stage: build\n  script: rake spec\n  needs: []\n  tags:\n  - ruby\n  - postgres\n  only:\n  - branches\n  - master\nrspec 0 2:\n  stage: build\n  allow_failure: true\n  script: rake spec\n  when: on_failure\n  needs: []\nspinach:\n  stage: build\n  script: rake spinach\n  needs: []\n  except:\n  - tags\ndeploy_job:\n  stage: deploy\n  script:\n  - echo 'done'\n  environment:\n    name: production\ndocker:\n  stage: test\n  script: curl http://dockerhub/URL\n  needs:\n  - spinach\n  - rspec 0 1\n  when: manual\n  except:\n  - branches\nafter_script:\n- echo 'run this after'\n"
    }
  }
}

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• I have tested this MR in all supported browsers, or it's not needed.
• [-] I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

#333840 (closed)