Add strategy depend to trigger api and update docs

• Please check this box if this contribution uses AI-generated content (including content generated by GitLab Duo features) as outlined in the GitLab DCO & CLA

What does this MR do and why?

Closes #31566 and reopens !110954 (closed)

This change adds a strategy parameter to the API and updates the API docs to call out how to use this parameter. When this feature was introduced https://gitlab.com/gitlab-org/gitlab-ee/issues/11238 it added a new strategy parameter, but this wasn't added to the API. This prevents some users of the curl command from performing this basic task using the API. Currently, the status of the triggered pipeline can't be tracked in any way so the users don't know if the triggered pipeline was successful or not.

Screenshots or screen recordings

N/A

How to set up and validate locally

N/A

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.