Add graphql support for adding default milestone title values

Currently, in graphql, we are able to filter board lists AND board list items by ANY and NONE milestone, using the milestoneTitle field. However, it is not currently possible to use STARTED or UPCOMING and the milestoneTitle is not the correct field for this query anyway.

Instead we should implement a milestoneWildcardId field, which accepts the STARTED, UPCOMING, ANY, and NONE types.

This issue should add this field, probably to the BoardIssueInputType so that this query is possible:

query boardsFiltered {
  group(fullPath: "gitlab-org") {
    board(id: "gid://gitlab/Board/1896794") {
      id
      lists(id: "gid://gitlab/List/5491995", issueFilters: { milestoneWildcardId: STARTED }) {
      	edges {
          node {
            id
            issuesCount
            label {
              id
              title
            }
            issues(filters: { milestoneWildcardId: STARTED }) {
              edges { 
                node {
                  title
                  milestone {
                    title
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

An example of similar work is in !65932 (merged)