Reduce payload sizes

[ob6160]

I think we can shave off 100kb or so by using zlib to deflate the loo data bundle as a brotli compressed base64 encoded string.

Before we resort to that there are some more fundamental things we can do:

• Map each id (example: 9844d4b07d20802345eda8d4) to a sequential number (mongoid??).
• We could alternatively use the creation date/time timestamp to reference the toilet. That's 13 bytes instead of the current 24 bytes
• OR! We could run a migration across our mongodb database so that all of our loos use small ids: https://github.com/ai/nanoid/#security
• See if we can represent the location of each toilet in another way. Perhaps look into using "quadkeys" to represent the tile at a specific zoom level that the toilet resides in (https://github.com/joekarl/binary-quadkey#space-comparison)
  • Q: is this accurate enough?

[ob6160]

superceded by #1452