METR-22322: add geo distance function

Corrected tests whose sensitivity may have degraded after introduced squashing blocks on INSERT by default [#METR-21877].

Dockerfile: "sh: 1: ulimit: error setting limit (Operation not permitted)" error fixing

Improved package build time; consistent package size across different Ubuntu versions [#METRIQA-72].

   I cannot run container on the latest Docker (1.12.0, build 8eab29e) because of error. The latest docker supports setting ulimits through the command line --ulimit nofile=262144:262144.