Fix/work package index performance

Dynamically includes the columns required for the fields in the response to various experimental work packages actions to be eager loaded.

This removes some n+1 queries, those when custom fields are involved in particular. In addition, it also does no longer load data that is not used later on.

https://community.openproject.org/work_packages/17550
@ulferts `column_names.grep(/cf_\d+/).any?`