Privacy: add means to erase personal data by username or email address. First run.

Props allendav, coreymckrill, ericdaams, azaozz.
See #43637, #43602.

git-svn-id: https://develop.svn.wordpress.org/trunk@42986 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/admin-ajax.php

@@ -130,6 +130,7 @@ $core_actions_post = array(
 	'get-community-events',
 	'edit-theme-plugin-file',
 	'wp-privacy-export-personal-data',
+	'wp-privacy-erase-personal-data',
 );
 
 // Deprecated