Highlight entry in My Submissions Tab

### Description
This issue is a revival of #2142.
The idea is that the participants are not able to see the highlighted submissions on their "My Submissions" page which correspond to the entry shown in the leaderboard. This feature helps the participants easily get to their corresponding submission

### Pre-requisites/Learnings
This issue essentially requires background on a few things:

- An overall understanding of [EvalAI challenges](https://evalai.readthedocs.io/en/latest/host_challenge.html).
- An understanding of the models related to [Challenges](https://github.com/Cloud-CV/EvalAI/blob/master/apps/challenges/models.py) on EvalAI.
- An understanding of the [EvalAI frontend](https://github.com/Cloud-CV/EvalAI/tree/master/frontend).

### How to Approach
- You can start by setting up EvalAI locally. Set up the dev version locally (preferred) using the steps [here](https://github.com/Cloud-CV/EvalAI/tree/master#installation-instructions).
- There can be various ways to approach this. Please feel free to make an attempt at this and create a PR (with screenshots).
- Reach out to us regarding any issues that you face or if you need any help with understanding any of the above.

Getting started and asking for help is the best way for this one :)