0.12.3

Fixes:

• Removed the 10-item limit per envelope for non-session data. Sessions are now limited to 100 per envelope, while other items (e.g., attachments) have no limit in amount. (#1347)
• Align the breakpad interface changes introduced with #1083 with the corresponding iOS build. (#1465)
• Add structured logs to debug output when debug option is set. (#1466)