Improve Test Coverage for challengeHostTeamsCtrl.js (Current: 70.51%)

**Description:**

The file EvalAI/frontend/src/js/controllers/challengeHostTeamsCtrl.js.js currently has 70.51% test coverage (as per Codecov). To improve this, comprehensive unit tests need to be added targeting untested and partially covered functionality

Start by reading EvalAI/frontend/src/js/controllers/challengeHostTeamsCtrl.js.js and use the Codecov report to identify untested and partially covered functionality. Add comprehensive unit tests for those areas, then rerun the relevant test and coverage checks to confirm that coverage improves beyond the reported 70.51%.

Written by the indexing model from the issue text.