Add published param to Page

[k-yomo]

This PR adds Published field to Page to make it possible to pass published parameter for create/update.
Also not to let user confuse, the field will be consistent with published_at when it's read.

curl -d '{"page":{"title":"Warranty information","body_html":"<h2>Warranty</h2>\n<p>Returns accepted if we receive items <strong>30 days after purchase</strong>.</p>","published":false}}' \
-X POST "https://your-development-store.myshopify.com/admin/api/2024-07/pages.json" \
-H "X-Shopify-Access-Token: {access_token}" \
-H "Content-Type: application/json"

https://shopify.dev/docs/api/admin-rest/2024-07/resources/page#post-pages-examples

[oliver006]

Thanks for the PR!
If the published field isn't returned than we should make it optional, e.g. nullable and not populate when we think we know what the value should be.
So let's just change published to *bool and no longer set it based on the published_at value when parsing a response and we should be good to go.

[k-yomo]

@oliver006
Thanks for the review!
I fixed published to *bool as suggested!

[oliver006]

Looks good - thanks for the PR!