Rewrite Front-End Tests to mock the New API

[Tguntenaar]

The current front-end tests are designed to mock the NEAR Query API, which has been used for fetching data in various components. However, with the deprecation of the NEAR Query API and the transition to a new API, we now need to rewrite the front-end tests to mock the new API instead. This ensures that our tests remain reliable and reflect the updated system architecture while maintaining test coverage for the front-end functionality.