[Feature Request] Add command line flag to embed linked svg files when exporting instead of using bitmap renditions

First, the new svg import options in 1.0 are great, thanks adding this feature!

When using inkscape to lay out complex external svg files, it is vastly improves performance to render them as bitmaps instead of embedding the svgs when importing. However, when exporting such inkscape documents, one has to choose between good resolution and large file size, or poor resolution and small file size since the bitmap rendering of the svg is used for the export rather than the linked svg file.

I think it would be very useful if there was a command line flag to use the linked svg file instead of the low resolution bitmap when exporting, something like: inkscape --embed-linked-files --export-type=pdf myfile.svg. For reference, I also opened a similar forum topic previously and discussed this in the chat before opening this feature request.

Version Info:

- Inkscape Version: Inkscape 1.0 (4035a4fb49, 2020-05-01) Pango version: 1.44.7
- Operating System: Arch Linux
- Operating System version: 5.7.2-arch1-1