Extend get_the_post_pagination() to consider total argument

[luludak]

Right now, the usage of the_posts_pagination() is associated directly with the Global query.
By investigating its code in ​documentation, I noticed that, it practically retrieves the pagination arguments expected by paginate_links($args), but it checks on global query ($GLOBALS['wp_query']) for the maximum number of pages.

However, one of the arguments of paginate_links($args) is total, which, by documentation is:
"The total amount of pages. Default is the value WP_Query's max_num_pages or 1.".

Since this exists as argument, my question is, why don't we check for the total in get_the_posts_pagination()? That way, we can allow its usage on custom queries (they can propagate the number of pages in the total argument), not using the global query at all - as this check can block the use of total as argument.

This fix can be made by changing this code in link-template.php:
if ( $GLOBALS['wp_query']->max_num_pages > 1 ) {}

into:

if ( (! empty( $args['total'] ) && $args['total'] > 1 ) || $GLOBALS['wp_query']->max_num_pages > 1 ) {

Note I did not remove the previous check on global query, to ensure backwards compatibility - paginate_links($args) uses global query to retrieve default arguments - so this part of code is useful. I also check for emptiness and then checking for the argument check in order to apply partial evaluation.

Please note I am adding this ticket for further discussion - since I am new to the community. If this is considered of value, I will be happy to work on the patch.