Multipage can ease animation workflow without needing much UI/UX work

Migrated from LPINK-1343411 - Multipage

Summary

These features can be implemented after supporting multipage to ease the animators' still using inkscape anyway.

Since supporting animation in inkscape requires much work - even on the UI front itself (see SpecsSVGAnimation🡭 from #2323 (comment 323161495)), and that doesnt seem to be coming anytime soon.

Feature

Use case:

• Multiple pages can be moved back/forth easily (with arrow keys),
• and hence with addition of some more functions like onion skinning, be made to function as frames (and exported/saved individually)
• This would hugely ease the animation workflow/pipeline.

Needed ToDo for this:

• Multipage support
• Saving pages as separate files - comment4
• Onion skinning UI - comment6

Other things/further external links:

• Reference tutorial - tympanus/svganimation
• Using some new tags to store the animation information - comment8
• Extension suggestion - sourceforge/inkpages - from comment9

Original description: #2334 (comment 323651208)