Add a routing tool

[gnw2t]

I think that a simple routing tool that tells the user how many ALPRs are on their route could be impactful. People could be prompted to see how much they are being tracked on their commute, or when going to the grocery store, or when dropping their kids at school.

I've been working on an implementation:

Performance is very good except for very long (i.e. interstate-scale) routes, which take a few seconds to compute but could be improved. Interested in people's thoughts of the usefulness of this.

[stopflock]

I think this is super cool especially if you have a PR for it! @frillweeman

[gnw2t]

Haven’t gotten a chance to work on this the past few days, should be able to open a PR tomorrow after some cleanup.