[experiment] Rename loop_XXX fields to evaluator_XXX

This makes them coherent with the algorithm types.
6 jobs for fix_loop_field_names in 48 minutes and 29 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #172166
docker-build
build_linux_36

00:22:51

64.0%
passed #172141
docker-build
build_linux_37

00:25:10

64.0%
passed #172138
macosx
build_macosx_36

00:25:17

64.0%
passed #172165
macosx
build_macosx_37

00:19:11

64.0%
canceled #172140
docker-build
build_linux_36

02:15:55

64.0%
failed #172139
macosx
build_macosx_37

01:30:01