Create a get_list_filter hook in ModelAdmin

[rasca]

This would be useful when for example the queryset is filtered based on a user type and the superuser can see all types. For a superuser one could add a the type field to list_display and list_filter.

[rasca]

Maybe also creating hooks for all the remaining ModelAdmin properties.

[rasca]

See also #17006 and #16841

[mateusgondim]

I created the hook there in options.py and replaced it in another method that was using the property directly.i also added a doc about the new method in the index.txt of admin, and in the section of minor features in release notes.Finally, i added a test in regression tests about that.

[Julien Phalip <jphalip@…>]

In ae206d78f6d991e1d7ea1c1bb8bd85f4658c0877:

Fixed #17646 -- Added a get_list_filter() method to ModelAdmin. Thanks to rasca for the suggestion and to mateusgondim for the patch.

[Julien Phalip <jphalip@…>]

In 22ca5bab95d65d0fdec0b6914f9ab96795cfe138:

[1.5.x] Fixed #17646 -- Added a get_list_filter() method to ModelAdmin. Thanks to rasca for the suggestion and to mateusgondim for the patch.
Backport of ae206d78f6d991e