Change user endpoint URLs and add API endpoints & logic for TodoList

Description

• Updated endpoint URLs for user endpoints
• Added logic for TodoList endpoints
• Added endpoint URL for TodoList as per https://git.uwaterloo.ca/p24saha/cs-346/-/wikis/api-documentation

Issue

#51 (closed)

Feature

Describe the feature or functionality added

Tophatting

Describe the steps to test your changes.

Expected current behavior

What should you see or expect when you test this feature?

Changes

Describe the changes you made part of this merge request

Screenshots

Showing user 1's list with listId 1 (user = 1, listId = 1)

Showing all of user1's lists (there are two of them!)

Design Patterns

List any design patterns used to accomplish this task

Deviations

Were there any deviations from the original design or architecture plan. If yes, what were they ?

Additional

• Unit test written
• Meets requirements
• Cross-browser tested
• Added/updated documentation as needed
• Camel case style used

Closes #51 (closed)