Update median exercise and add new throw/catch practice exercises

**Which module(s) and week(s) does this change affect?**
Module(s): Data Groups
Week(s): Sprint 1

**What is the work that needs to be done?**

`Sprint-1/fix/median.js` currently expects `calculateMedian` to return `null`/silently filter bad values, which now contradicts the error handling fundamentals content ([curriculum#1949](https://github.com/CodeYourFuture/curriculum/pull/1949)) that teaches throwing instead. Update this exercise to match, and add new exercises giving trainees practice throwing and catching errors.

**Why is this work important to do?**

Suggested by @illicitonion during review of curriculum#1949. Keeps exercises consistent with newly taught content.

**Additional context**

**Who might need to know about this change?**

@illicitonion