Issue 5: Join and share lists

Description

This PR adds functionality allowing the user to connect to an existing list.

User Facing Behavior

Adds a text input field to a form in the Home view, allowing a user to input a listToken. When this form is submitted, if the list exists the listToken is saved in local storage and the user is redirected to the list page. Otherwise, a message informs the user that the list was not found.

Firebase API

Adds a function to firebase.js to return the count of items in a collection. If the collection does not exist, the count will be 0.

Refactoring

Changed the AddItem view so that when a new item is added to a new list, firebase creates a new collection with the same name as the token in local storage.

Related Issue

closes #5

Acceptance Criteria

If a user doesn’t already have a token:

[x] The Home view shows a form that allows the user to enter a token to join an existing list, in addition to the button that allows them to create a new list.
[x] The input that accepts the list token has a semantic label element associated with its
[x] The user can submit this form with both the mouse and the Enter key
[x] If the list exists,
- the token is saved in localStorage
- the user is redirected to the List view and shown the items on that list
[x] If the list does not exist, the user is shown an error message that explains the problem

If a user does already have a token:

[x] They are automatically redirected to the List view.

Type of Changes

	Type
	:bug: Bug fix
✓	:sparkles: New feature
✓	:hammer: Refactoring
	:100: Add tests
	:link: Update dependencies
	:scroll: Docs

Updates

Before

After

https://github.com/the-collab-lab/tcl-65-smart-shopping-list/assets/71429289/e0c7ae2c-d540-4c88-97c1-db332bc71ef8

Testing Steps / QA Criteria

[x] Open the preview link provided by GitHub actions.
[x] Remove any listToken currently saved in browser local storage.
[x] Enter 'flout woman waxy' in the input field to attempt to join an existing list
[x] Check that the new list is visible and you can add an item
[x] Enter a different string in the input field to see that the list was not found.

the-collab-lab / tcl-65-smart-shopping-list