Add global action to get_template_part

[pcfreak30]

I would like to see

do_action( "get_template_part", $slug, $name );

in get_template_part. Right now there is no means to track or do any action on every template call. A feature I want to implement in a plugin relies on this to function how I want. As of now I can only get the primary template.

[SergeyBiryukov]

Related: #13239, #40258, #40508.

[joyously]

That is very similar to what is there now:
do_action( "get_template_part_{$slug}", $slug, $name );
but I can see that it would be difficult to do a generic action since the slug is part of the action name.
Reviewing themes, I have seen quite a variety of slugs used, mostly with a folder structure. This really does not lend itself to reuse.

[johnbillion]

I think it's time that this happened. It can really help with debugging and analysis.

[desrosj]

This ticket has not received any attention during the 5.2 cycle. With beta
1 tomorrow, going to punt this to 5.3.

[johnbillion]

Enough with the bumping.

[johnbillion]

In 45059:

Themes: Introduce a generic action that's fired when a template part is loaded.

This action allows debugging mechanisms to perform greater introspection into which template parts are loaded for any given request. It also exposes the array of candidate template part file names for each template part instance.

Props pcfreak30, jdeeburke

Fixes #41575