Work breakdown

• Factorize sqlite wrapper code (!15053 (merged))
• Implement version of sqlite store (!15026 (merged))
  • Design DB schema
  • Write prepared queries for each componenent/store
  • Wrap accesses to provide store like api
  • Tests
• Migration code from old to new store (!15059 (merged))
• Regression tests for schema (!15073 (merged))
• Compress some data (!15218 (merged))
• Migration in the background (!15257 (merged))