[CFM2_3] Update Fridge ID

[1jeanpaul1]

Ticket: https://trello.com/c/i5hqCMIO/267-cfm23-update-fridge-id-hash
Proposal: https://docs.google.com/document/d/1reJibvkEZw_rbzj82BgawbCy4iQLGpObGrkwPWT8SOA/edit?usp=sharing

Updates

• Updates the set_id function to use a random 6-character, URL-safe identifier, instead of the Fridge's name, for the Fridge ID
• Updates and adds unit tests to cover the new ID generation
• Updates README to reflect ID format
• Update Python Version from 3.9 -> 3.13 (Lambda is ending support for python 3.9)

TEST:

1. Local testing

• Follow README instructions to load fridges and start local server
• go to http://localhost:3000/v1/fridges
• Confirm that the IDs are now randomly generated characters
  

2. Unit Tests

• Follow README instructions to run unit tests
• Confirm that all tests were succesful
  

[1jeanpaul1]

Removed because we no longer can query on a predefined ID, id's are now randomly generated