Show jobs without needs in correct order in the job dependencies view

Summary

With the work already completed here, the purpose of this implementation issue is to show jobs without needs in the correct order in the job dependencies view. The backend work for this issue is to only take care of the order of the jobs without explicit needs in the job dependencies view. The links between the jobs with implicit dependencies should be hidden.

Proposal

from #330079 (comment 657835314)

We have a combinedNeeds array in the API.

{
  needs: [
    { name: "job_1" },
  ],
  combinedNeeds: [
    { name: "job_1", type: "explicit" },
    { name: "job_2", type: "implicit" }
  ]
}`

The naming here is tricky, but this allows us to use the benefits from approach 1, without breaking the current API implementation. Having the needs in two places feels a little strange, but maybe we can get around that by deprecating the original one and phasing it out for the next major release.

Availability & Testing

• Unit test changes - Required unit tests to be updated according to changes
• Integration test changes - Required test for API request returns body as expected with explicit and implicit jobs in correct order.
• End-to-end test change - not required
• package-and-qa should be run in MR with these changes to ensure no regressions is introduced.