Get RouteBuilder ready for prime time

[misaugstad]

Brief description of problem/feature

I made a really basic version of RouteBuilder in PR #3150 with some improvements in #3154 and #3159. After getting some time to test it as part of our validation study, I've identified some things that need to be added before it's ready for prime time (and by that, I mean adding it to the navbar for anyone to find). I have a more detailed list in my notes, but this is broadly what we need:

1. Improved routing. The routing has all the problems that we have when finishing a neighborhood, plus some other newly introduced (or revealed) edge cases. Not great!
2. There are some confusing visual bugs on the mini map and mission complete map to fix.
3. Clean up the RouteBuilder UI. It's still not going to be great, but there are some absolute basics we need, like informing the user that their route was saved with a tooltip.
4. Add logging and code comments.
5. Add at least temporary translations with Google Translate.

At the time of writing, I've actually finished (1) and (2) on the routebuilder-updates branch. Thankfully those are the most complicated and time consuming, so the rest should be pretty quick!