Staging minor convenience functions

[0xDBFB7]

Hi Floris!

Minor bugs added edits made towards #9 [Apologies for my previous frenetic reply there :)], figured I'd break up the PRs.

• Waveforms split out into new file, new ones added
• Little helper function in boundaries
• Backend-parameterized testing
• File with reduced units as in readme and thesis, not really necessary

This hasn't been extensively tested beyond units and lints, just pulled out of master; if it looks satisfactory you can keep it open until the next PR if you like.

Thanks for this great lib!

[flaport]

Looks good, thanks! I'm excited to see what's coming next 😉

Shall I merge this already? Or do you want to keep on working on this PR? (either is fine for me)

[flaport]

merging this as it's a prerequisite to #27 which will remain open for the time being.