Pass `$userdata` to the actions and filters in `wp_insert_user()`

[johnbillion]

There are several actions and filters inside wp_insert_user() which would benefit from being able to access the raw $userdata array that's passed into the function.

One use case is extending the wp user import-csv command in WP-CLI. This command is a wrapper for wp_insert_user() but it's not possible to provide custom user meta fields because there's nowhere inside wp_insert_user() where a plugin can access the raw data array in order to add the user meta.

Trac ticket: https://core.trac.wordpress.org/ticket/53110

[audrasjb]

+1 for this proposal. Just figured it out while I was working on #53109.

The PR looks good to me :)

[desrosj]

In 51005:

Users: Pass on the user data received by wp_insert_user() to related hooks.

This adds a new parameter to the action and filter hooks found in wp_insert_user() to pass the raw user data received through $userdata to hooked functions.

This will allow hooked functions to perform more contextual adjustments to new users, and makes supplying custom user meta fields possible.

Props johnbillion, audrasjb.
Fixes #53110.

https://core.trac.wordpress.org/changeset/51005