Add Sentry logging

[Venefilyn]

For logging, add Sentry for both back-end and front-end to find errors faster.

Since this might need to call custom Sentry methods for logging, I would suggest to simply add it to the project and make sure it works by adding simple logging for files that will rarely change as to avoid merge conflicts.

• Sentry is added on front-end.
• Sentry is added on back-end.