Add a title to forest plot download, with the outcome included in the title

This would be helpful when you have several outcomes. Currently downloaded forest plots can only be distinguished by the filename (if you change it from the default).

Start by locating the code that generates and downloads forest plots, then trace how the selected outcome is available when the plot title is built. Update the downloaded plot title to include the outcome, and verify that downloads for several outcomes are distinguishable without relying only on filenames.

Written by the indexing model from the issue text.