Break down string methods workshop and add it to main

This workshop is dedicated to practice string methods and will be placed right after an introductory workshop on strings.

Here's the prototype: https://github.com/freeCodeCamp/CurriculumExpansion/blob/main/fullstack-cert/python-projects/strings-workshop-2/main.py

## This issue is part of Naomi's sprint initiatives.

If you are interested in working on this issue, [join our Discord](https://chat.freecodecamp.org) and ping Naomi!

### Action Items

- [x] Prototype created and PRed to https://github.com/freeCodeCamp/curriculumexpansion
- [x] Prototype reviewed + approved + merged by staff
- [x] Break prototype down into steps (if workshop) or individual "step" (if lab) - write description, hint text **only** (no tests yet), and seed code. Refer to https://contribute.freecodecamp.org/how-to-work-on-coding-challenges
- [x] DRAFT PR opened on https://github.com/freeCodeCamp/freeCodeCamp
- [ ] Team + Naomi review your steps, confirm the breakdown + user stories look good
- [ ] Begin writing the actual test logic, refer to https://contribute.freecodecamp.org/curriculum-help/#basic-usage-pattern for how to write tests for Python challenges
- [ ] Mark PR as not a draft, team reviews + approves + merges
- [ ] YOU DID IT GO CELEBRATE!

### Other Details

- Remember to keep an eye on your PRs and respond to review comments and suggestions
- For workshops, refer to: https://contribute.freecodecamp.org/how-to-work-on-coding-challenges/
- For labs, refer to: https://contribute.freecodecamp.org/how-to-work-on-labs/

### Questions

Ping Naomi in the sprint channel on Discord