fix(tests): normalize suite names to lowercase snake_case (E617)

All test suite names now follow the convention: lowercase snake_case
matching the test filename. Changes:
- crowbar examples: 'crowbar' → filename (calendar/fpath/map/pprint/uunf)
- irmin: uppercase suites → lowercase
- memtrace: uppercase/mismatched → lowercase matching filename
- monopam/ocaml-agent/ocaml-aos/ocaml-conpool/ocaml-cookeio/ocaml-crow:
uppercase → lowercase
- ocaml-crypto: 'cipher' → 'crypto'
- ocaml-github-oauth: 'github-oauth' → 'github_oauth'
- ocaml-jsonwt/ocaml-linkedin/ocaml-merlin: mismatch fixed
- ocaml-oci: rename test_OS.ml/.mli → test_os.ml/.mli, suite 'OS' → 'os'
- ocaml-precommit: 'hooks' → 'precommit'
- ocaml-sexpt: 'dune_codec' → 'dune'
- ocaml-slack: 'md' → 'markdown'
- ocaml-sle: 'FCLTU' → 'fcltu'
- ocaml-space-packet: 'space-packet' → 'space_packet'
- ocaml-tls: 'tls-eio'/'tls-unix' → snake_case
- ocaml-tomlt: 'tomlt-*' → snake_case