Allow to choose additional fields to show in the search result view

Currently the result view allows to choose a field for title and description and then either show all remaining fields or nothing at all. This is very limiting, very often a small number of many available fields would be extremely helpful to include in the output. Even just adding a fixed number of additional "Select" options, e.g. "Select Field1", "Select Field2", ... which are either unused (Choose option) or set to a selected field would be very helpful.
Alternately, there could just be a simple input field listing the names of the fields to show in addition.

Start at the search result view entry point and trace how title, description, and remaining fields are selected. Confirm the existing field-selection behavior, then define the additional-field controls from the issue and verify that selected fields appear in the results without changing the title or description behavior.

Written by the indexing model from the issue text.