Add field in project type to return timeline event tags

What does this MR do and why?

With this MR, the project query can return the incidentManagementTimelineEventTags field.

Screenshots or screen recordings

NA

How to set up and validate locally

1. Make sure you have read access to a project.
2. Create a few tags by following the steps mentioned in !102870 (merged).
3. Add the below query to fetch project details and add the timelineEventTags field with the below input.
4. Check the return values.

Query

query GetProjectDetails($projectPath: ID!) {
  project(fullPath: $projectPath) {
    id
    incidentManagementTimelineEventTags {
      name
      id
    }
  }
}

Sample input

{
  "projectPath": "<project_path where tags were added.>"
}

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.

Related to #373853 (closed)