Deprecate user_view and user_view_multiple

Problem/Motivation

user_view and user_view_multiple are unneeded procedural wrappers around other deprecated procedural wrappers. Neither method is used in more than one or two places in core, and they should be refactored and the methods deprecated and marked for removal in Drupal 9 in favor of using entity objects and entity storage for deleting.

Proposed resolution

Deprecate both functions and trigger an error on use

Remaining tasks

do it.

User interface changes

none.

API changes

user_delete and user_delete_multiple are deprecated and scheduled for removal in Drupal 9

Data model changes

none

Release notes snippet

Procedural methods user_delete and user_delete_multiple have been deprecated and will be removed in Drupal 9