* [sqlite] Added has_content column and relevant migration
* Fix typo in docstring
* [sqlite] Fetch content for bookmarks separately
* [sqlite] Store has_content alongside with bookmark
* [sqlite] Rename variable to distinguish it from main query
* [sqlite] Use by-reference instead of no-op copy
* [sqlite] Reduce queries count from ≈30 to 1 to fetch tags
* Lint fixes
* Make minor logging improvements
* Wrap entire migration in transaction block
* Added «down» migration
* Drop workaround for old SQLite versions