eps export should have non-tight bounding box (or clarify that it doesn't)

Migrated from https://bugs.launchpad.net/inkscape/+bug/170458 🍷

Original title: Export to EPS: selection only

Steps to reproduce:

• Invoke "Save as..." or "Save a copy..." and choose .eps as output format
• Choose any the PS Level, Text Output, Rasterize and Bleed options as necessary
• Select "Output page size" option (Document page/Exported object)
• Press "OK"

What happened?

.eps is saved to drawing size, regardless of size settings. It dosn't even respect the misleadingly-worded "Exported object": what does that mean? Is the entire drawing now considered an object where in every other reference to "object" in Inkscape is each separate...well, object, be it a path, a rectangle object, an ellipse object or a text object. Otherwise, it's a group...or a drawing...or a page.

What should have happened?

• Inkscape should respect output size setting
• Inkscape should offer Output options: Page/Drawing/Selection/Object ID in a clear, non-programmer manner

Steps to reproduce:

• Create a group of objects
• Invoke "Save as..." or "Save a copy..." and choose .eps as output format
• Choose any the PS Level, Text Output, Rasterize and Bleed options as necessary
• Enter the group ID in "Limit export to the object with ID ____"
• Press "OK"

What happened?

Inkscape outputs a blank .eps document with the dimensions of the identified group

What should have happened?

Inkscape should output a document with the ID'd group

Inkscape Version and Operating System:

• Inkscape Version: lasted tested with
  • 1.0beta2 (074b463, 2020-02-02)
  • 0.92.4 (5da689c313, 2019-01-14), MacPorts
  • 0.92.4+68~ubuntu18.04.1
  • 1.1-dev (969dcdb233, 2020-03-27), snap package
• Operating System: macOS/Ubuntu
• Operating System version: 10.12.6 (16G2136)/18.04.4 LTS

Additional Information/Comments:

• Probably related: inkscape#996
• It appears (summarily) this problem does not exist for saving to .pdf