Allow all valid email formats when editing accounts in the dashboard

[chrisl27]

When updating an email address in the dashboard wp-admin/includes/user.php:80 uses sanitize_text_field which strips out a substring like "%ed" even though that is valid in the local part of an email address. Eg, the valid email address "user%edition@…" is saved as "userition@…".

This ticket requests to using sanitize_email instead, similar to the REST API that checks using is_email.

(A related, fixed issue is in #18039 which also recommended using sanitize_email)

[chrisl27]

Patch