I've converted the improveOSM errors to use this new generic QA error
structure which should allow for more general code to be used in
behaviour and UI.
Sidebar preview is currently broken, but will be fixed shortly.
As per my last commit, this icon differentiates errors from points and
still allows us to specifiy icons for errors to differentiate them amongst
eachother.
I learned quite a bit about SVGs and using them in HTML while
implementing this 😝Had some issues getting the icon to center in the
header so resorted to using a flexbox instead of absolute positioning
being used elsewhere.
