Provide easier way to export a subset of components

Currently, we can set prevent graphical items from being exported by setting "Export As"="Skipped".

However, this "Skipped" flag is persistent, and is part of the project metadata itself. It would be helpful for the customer to be able to export a small selection of items (say, for a quick inspection of a section that is actively being worked on) without modifying the project metadata.

Perhaps a separate "Export Selected" button which only exports the currently-highlighted items?