[FEATURE] Drag and drop symptom ordering

[actastron]

When adding flow symptoms my instinct is to select from high to low in order of volume, however they're ordered alphabetically which threw me off a bit.

I got around this by prepending numbers to the descriptions so they're in the order that I want, however drag and drop ordering would be nice enhancement.

[carstenhag]

I think it's a valid point, but the workaround of manually adding numbers is also fine. We need more feedback on this imo.