Rename `id` param in get_the_permalink, get_permalink, and the_permalink

[chriscct7]

The id param in get_the_permalink, get_permalink, and the_permalink isn't very intuitive. id is not a really good parameter name, partially because it doesn't actually describe what it is. Is it a post id? A user id? A random number called id? A serial number for a bikeshed? A MySQL column that autoincrements value?

If the id param was renamed to post it'd make the functions more self-documenting, and would require a minimal effort patch, making the functions more easily understood for newer developers by saving them the time of figuring out what exactly id is.

[DrewAPicture]

In 35001:

Template: Rename the $id parameters in the_permalink(), get_the_permalink(), and get_permalink() to $post.

In all three cases, the functions can accept a post ID, a WP_Post object, or a falsey value, which defaults to the value of the global $post. Switching to $post in this context allows the parameters to better self-document and removes ambiguity in the code they are subsequently used in.

Props chriscct7 for the initial patch.
See #34234.

[DrewAPicture]

In 35002:

Template: Pass the $post parameter to the the_permalink filter.

Props chriscct7.
Fixes #34234. See #23882.