[ORCA-3475] Make event orchestration team ID a nullable field

[alenapan]

Changes

In order to reset the team ID on orchestration the PUT endpoint payload should look like this:

{
    "orchestration": { 
        "name": "Orch 1",
        "team": {
            "id": null
        }
    }
}

With team.ID being string instead of *string we couldn't set ID to nil (because Go doesn't allow assigning nil to variables of type string) and had to use an empty string instead, which is not supported by the API.

This PR makes the team Id property a pointer to the string type that allows us to set it to nil when necessary.

Testing

[tyurina]

Got bored of my ticket so I decided to review this one 😅 , nice I learned a lot from this https://www.sohamkamani.com/golang/omitempty/