[SQLiteBaseDatabase] Make the instances picklable

2 jobs for sqlite-picklable in 5 minutes and 46 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #218975
docker
build_linux_37

00:02:44

55.0%
passed #218974
macosx
build_macosx_37

00:05:46

55.0%