feat(draw-route): Base stencils for other categories
Merge branch 'import-export' of github.com:mozilla/seasponge into stencils
feat(draw-route): implement stencils as outline in proposal
chore(draw-route): Clean up redundant definitions in stencils
Merge branch 'stencils' of github.com:mozilla/seasponge
feat(draw-route): implement support for Flows

See #22.
- (de)serialize and render Flows