Create API endpoint for eligibility of teams for advancement.

**Describe the solution you'd like**
Right now, there is no way it the API to see which teams are eligible for advancement/inspire. The /advancement shows which teams have already advanced/ineligible, however there is no way of knowing until the advancement data comes in and that too only for the teams that have advanced. Having a endpoint like /eligibility or something would be helpful when creating a advancment feature in other third-party scouting apps.