Automated test cases for simulations repo page

[JithinKS97]

The idea is to ensure that all the recently developed features in the simulations repo are working correctly

1. Searching for sims
2. Editing of the sims
3. Showing the details of sims
4. Adding sims to lessons

Before we take up this, we should finish the authentication on the client-side.
With sims repo change, test coverage went from 89% to 80%. We need to bring it to >90% 💪