Reconcile metadata DB schema: use the same between Apollo/Gemini

[bzz]

To reconcile metadata schema and use the same one between Apollo/Gemini we need to:

• Apollo: bucket meta by path Change DB schema to allow for same SHA \w different path in a single repo apollo#21
• Apollo: unify formatting \w Gemini URLFormatter, bucket by ref_hash/commit Reconcile Meta DB schema and output \w Gemini apollo#22
• Gemini: refactoring, for consistent naming in code i.e ref_hash->commit Refactoring: reconciling schema \w Apollo Meta DB #48
• Gemini: change default keyspace/column names in schema to match Apollo ones
• Gemini: add Go query to the CI