fix(cookie): Use the shop cookie name for default route

[alexisvigoureux]

Description

In addition to this PR
#2482

Here is the cookie naming behavior:

• If not setting the authOptions.cookieOptions.name parameter:
  • Both the Admin API and Shop API cookies names will be the default one: 'session'
• If setting the authOptions.cookieOptions.name parameter to something like 'cookie-name':
  • Both the Admin API and Shop API cookies names will be the configured one: 'cookie-name'
• If setting the authOptions.cookieOptions.name parameter to something like {shop: 'cookie-name', admin: 'admin-cookie-name'}:
  • The Admin API cookie name will be 'admin-cookie-name'
  • Shop API cookie name will be 'cookie-name'
  • And all the REST endpoints on the / route will use the default cookie: 'session'
    • context: some systems do not support Graphql and so we have a few REST endpoints. This PR allows to use the same shop cookie name for graphql and REST routes

Breaking changes

I think it's an unintended behaviour that can be released in the next patch

Screenshots

Checklist

📌 Always:

• I have set a clear title
• My PR is small and contains a single feature
• I have checked my own PR

👍 Most of the time:

• I have added or updated test cases
• I have updated the README if needed

[netlify]

❌ Deploy Preview for effervescent-donut-4977b2 failed.

Name	Link
🔨 Latest commit	0a657e0
🔍 Latest deploy log	https://app.netlify.com/sites/effervescent-donut-4977b2/deploys/6639eded7e2e4300096ff148

[michaelbromley]

Thanks!