feat(ios): store databases in Application Support safely

[chrispader]

iOS apps that expose Documents through file sharing also expose Nitro SQLite databases, but moving those databases without every SQLite recovery file can corrupt data after a crash. #323 adds an opt-in Application Support location, but its migration omits rollback journals and only applies to databases passed through open(). This replacement keeps Nicolás Bonet's original commit and adds complete recovery-file handling plus consistent open(), attach(), and drop() behavior.

• Migrates the database, rollback journal, WAL, and shared-memory files as one set.
• Removes stale destination journals before copying and keeps using the source after any inspection, cleanup, copy, or deletion failure.
• Migrates databases before attach() and removes old or partial generations from both locations during drop().
• Adds C++ regression tests against the bundled SQLite, including real WAL and hot-journal recovery after an unclean process exit.

Reproduction

1. Create primary and attached databases with a version that stores them in Documents.
2. Leave either a rollback journal or WAL files beside a database, then install a build with RNNitroSQLite_DatabaseLocation set to ApplicationSupport.
3. Open or attach each database and verify the database and its journal files move to Application Support without losing data.
4. Delete a database whose migration was interrupted and verify no old or partial generation remains in either location.

Fixes #289.
Supersedes #323.