5756: replace metriks gem with codahale metrics

this also removes MRI support and obsolete extensions
fix metrics integration
convert metrics to module to prevent multiple registries
remove old statistics class
be compatible with previous metriks logger
make bundler optional for CI
update gemlock
add some deps
update gemfile.lock
revert some stuff
remove lookjar for testing
remove lockjar task
foo
foo 2
cleanup lockjar mess
add lock_jar for development